SONOFF SenseGuard SNZB-09P Zigbee Indoor Siren

Loud, responsive, and works great with Home Assistant

I really like this SONOFF siren. It’s super loud, responds quickly, and works extremely well with Home Assistant. I’ve already created several automations with it that have been really useful around the house.

I keep mine plugged into USB-C power, so battery life hasn’t been a concern. It can also run on batteries, but I haven’t tested how long they last.

Like my other SONOFF devices, it works with my Home Assistant setup without subscription fees. I appreciate good-quality hardware that works with an open-source system and lets me decide how to use it.

Great for alerts and home security automations. Very happy with it and highly recommend it.

Useful addition to Zigbee devices

This is a versatile addition to my set of Zigbee devices. I paired it very easily using Zigbee2MQTT by simply powering up the siren while the software was in pairing mode. It took about 30 seconds for the siren to be found and then another 30 seconds for it to be fully added to my device list. Make sure to check the product description for notes about the minimum version of Zigbee2MQTT required for this device - I happened to have the minimum compatible version already and it worked fine.

I found the flashing LED and siren to be more than adequate, with both of them having settable properties that makes it very customizable. To test the device, I sent it some MQTT JSON payloads to flash the LED and sound the siren at various volumes. It can get loud! I'm looking forward to setting up various automations in Home Assistant to trigger this siren. With all of the available settings and features, there really is no end to what you can do with this item. At the current price it seems like a good value and lots of functionality for the money.

0:03

Functionally loud siren

Great alarm. I have it added under ZHA in Home Assistant. It has a battery backup and a plug for USB-C wired power. It works well and all the sensors show up. I am able to configure the alarm to go off based on different triggers in my Home Assistant controller. It connected immediately the first time and has worked well since. The alarm is very loud coming through the speaker.

Works Well in Home Assistant ZHA if Quirk is installed

Quick Facts:

Device Type: Zigbee Siren (End device only)

Power Source: USB-C (cable included, power adapter not included) with internal backup battery

Sound Output: Up to 105 dB (adequate volume, not piercing)

Integration Tested: Home Assistant via ZHA (requires custom quirk for full control)

Key Entities: Independent siren and strobe controls, tamper alert entity

I picked up this Zigbee siren for my garage where I wanted a loud intrusion alarm. The package includes a USB-C power cord and mounting hardware, but it does not come with a power supply adapter. It runs on USB-C power and features an internal backup battery that keeps it running if the power goes out. Even when continuously powered via USB-C, it only operates as an end device rather than a Zigbee router.

Pairing to Home Assistant via ZHA worked immediately; however, out of the box, much of the functionality was missing. Even though controls are exposed, you cannot natively adjust the tone, volume, or lights, leaving you with only the default siren at maximum volume. Installing a custom Zigbee quirks file (SNZB-09P.py) restored most of the missing functions, although several odd behaviors remain. When connected to USB-C power, the siren is always on regardless of the physical switch position, as that switch only dictates battery operation. Additionally, Home Assistant does not report the battery level while the unit is plugged in, so checking the charge status requires unplugging the cable.

Home Assistant exposes a tamper entity that detects when the unit is removed from its mounting bracket. That entity only triggers if the unit is plugged in or switched on, which means anyone can trivially bypass the alert by switching it off before unplugging it. In actual testing, the siren output was adequate for the garage space, although not quite as piercingly loud as expected for a 105 dB rating. I appreciate that the strobe light and alarm audio can be triggered independently, making it easy to configure silent visual alerts alongside standard alarms. Overall, the value is very good for a local Zigbee setup once the quirk is in place.

Positives:

✅ Internal backup battery maintains operation during outages

✅ Independent siren and strobe light controls via quirk

✅ Fast initial pairing in Home Assistant via ZHA

✅ Adequate sound output for garage coverage

Negatives:

❎ Requires a custom quirk in ZHA for advanced controls

❎ Operates strictly as an end device without routing

❎ Battery charge status hidden while connected to USB-C

❎ Tamper entity easily bypassed by switching off battery power

High intensity Zigbee alarm

I wanted to add an alert indicator to my Home Assistant setup for things like water leakage alerts and this Sonoff siren works pretty well for that purpose. It feels solidly made and the price is reasonable. While I had some difficulty with the initial setup until I figured out the quirks had to be setup up, things connected smoothly and setup up easily to my HA system after that. It seems intended more as a security alarm as it has very loud siren and bright lights and I will be using it at the lowest volumes and intensities. Perhaps this is a down side for my type of use as this requires more power and thus it uses a rechargeable battery with good but not outstanding battery life. I would of preferred a lower power device with longer battery life and replaceable batteries. While this can be worked around by using the wired USB option, I suspect that will degrade the life of the battery as it will by constantly charged at 100%. It would be nice to have a wired power setting that did not charge the battery or kept it at a lower level or charge.

Loud Zigbee siren ideal for custom Home Assistant setups

I have been using Home Assistant for over a year now and am starting to grow my collection. SONOFF is definitely one of my preferred brands, with several other devices being successfully used from them and this device connects and is compatable, no issues. I have started a second Home Assistant buildout in my camper van, including some automations, and am now starting on the security buildout. I am using this alarm for an in-van siren tied to some monitoring devices that can be heard and seen when certain devices are activated. There is no problem hearing the siren from outside the van, as the alarm is very loud. As another reviewer noted, if using ZHA, you need to follow the SONOFF script to expose the full feature set.

The unit supports dual power options via a 5V Type-C port or an internal lithium battery, making it easy to mount almost anywhere without relying on constant grid power. The built-in speaker reaches up to 105 decibels across 5 adjustable volume levels, ranging from a quiet notification chime up to a full-blast alarm that deters intruders. It features 10 different sound effects, and you can individually toggle the red visual light, customize the alarm duration, or run it in silent mode for background alerts. The plastic housing is compact, sturdy, and mounts easily to walls or cabinet panels with the included hardware. When linked with door contacts or presence sensors in your setup, it responds quickly over Zigbee without noticeable trigger delay.

The light ring provides clear visual feedback alongside the audio, which helps confirm system armed states at a glance. Something I find helpful is adding the custom ZHA quirks or script parameters right away so you can unlock controls for volume levels, light settings, and tone selection directly in Home Assistant. Given its build quality, backup battery capability, and seamless integration into smart home platforms, this siren is a very good value for the cost.

Works great, even with Hubitat

The Sonoff Zigbee Siren can run on builtin rechargeable battery or be plugged in. It connected very quickly to Hubitat over zigbee. It connected as a device and a driver had to be installed from Hubitat community. All the statuses work along with multiple options to set. The siren is very loud in my testing. The brightness seems to be ok, but more of a quick warning lights but not super bright. It will get your attention at night, but not so much during the day. It is compatible with Smartthings as well. Overall good for the price. I paired it with my water leak sensors to alert me when there is a leak detected.

Carl Douglas

August 18, 2026

Finally, a Zigbee Siren!

I’ve been using Home Assistant for several years and am very familiar with Sonoff products. I was genuinely excited when I saw this because people in the Home Assistant community have been asking for a good Zigbee siren for a long time. Until now, my alarm setup has basically used car alarm horns connected to smart plugs and triggered through Home Assistant. This is a much cleaner solution.

Setup was mostly straightforward, although I did have some trouble initially with Zigbee2MQTT. My first few pairing attempts failed, and after I finally got it added, the siren became unresponsive during testing. I deleted it, paired it again, and noticed an OTA firmware update was available. After installing the update, it started working properly and has been reliable since.

This thing is ridiculously loud. Honestly, it’s almost dangerously loud when you’re anywhere near it. I was surprised to find that Zigbee2MQTT even has a setting that allows the volume to be turned up higher.

There are also plenty of controls available in Home Assistant. I can independently enable or disable the siren and flashing light, adjust the alarm duration, change the siren tone, and control other settings directly through Zigbee2MQTT.

I also really like that it can be battery-powered or hardwired, which gives you a lot more flexibility in where you install it. Everything needed to mount it is included. I do wish Sonoff had given it a built-in magnet like some of their other sensors, though. That would make mounting and removing it even easier.

I’m really happy Sonoff finally made something like this, and I’m excited to integrate it into my Home Assistant alarm system. Now my one request for Sonoff: please, please make an outdoor version.

Works in Home Assistant ZHA with quirk. Brand new release and still needs a little more work.

I got this to use within my Home Assistant system under ZHA so my review is mostly from that side. It's a relatively new product at this point. As such, you'll need to download and add a quirk/script available on Sonoff's site to make it work well under ZHA. Instructions are provided and it's relatively simple to do. Same as any other Zigbee quirk. I tried without to see how it would do and there are some things that weren't quite right. Apply the quirk first and it should pull in fine (mostly). The first time that you turn it on it will be in pairing mode and flashing. You also can hold the "Set" button to start the pairing. HA picks it up very quickly when pairing and the interview/config process went smoothly. It comes into HA as a switch. You can change that to call it a siren for automation purposes if you want.

After installing with the quirk it's worked OK for the most part but at times will be very slow respond to being switched on/off. A few times when that's happened it's displayed an error saying that it failed to activate the siren. I've not completely tested it but seems to happen mostly when toggling the switch within the integration multiple times within a short period of time, but it's also happened at least once on first touch. I noticed it mostly when clicking through things trying different sounds. I don't think that I've seen a case where it didn't work via an automation other than after already confusing it first via the toggle and it getting behind. Also, the firmware version shows as unknown.

After you have it in and working, the first thing that you should do is set it to low and, after testing a few sounds, disable the sound and use the light only for testing purposes. ; ) This thing is LOUD for its size. Quite a bit louder than another Z-wave siren that I have. Even at lowest settings it's still fairly loud. I'd like to see a numeric/percentage level that could be taken lower. Also, I was hoping that there was a simple chime or other softer sound to maybe use for entry/exit or other purposes but that's not one of those included. They're all kind of abrasive siren/alert tones. Which I suppose is appropriate for an alarm siren. But it limits other uses.

It's a well-made piece. Fit and finish are very good. About 3" diameter x 1.5" high. Will run on battery or wired USB-C @ 5v. You can turn off the battery power with the on/off switch. A cable and mounting screws are provided. It mounts by a twist-to-lock type ring at the rear/bottom.

Price is good for what it is I think. Don't see many Zigbee sirens. After an update/being merged into ZHA, I'm sure that it will be as solid as everything else that I've had from Sonoff.

Loud, bright, and impressively flexible with Home Assistant

This little siren is awesomely LOUD and BRIGHT. Even its lowest volume setting is plenty noticeable indoors, and there are enough combinations of alarm sounds, volume levels, and flashing-light behavior to make it useful for far more than a simple security alarm. SONOFF specifies four volume levels of roughly 75, 82, 93, and 105 dB at one meter, along with ten selectable sounds, and sound and light can be controlled independently or used together.

Integration with Home Assistant using ZHA was straightforward, but there is one important lesson from my setup: read the detailed online documentation before pairing it. I initially paired it normally and got a useful but incomplete set of features. SONOFF's documentation specifically notes that ZHA currently requires their supplied script, and following those instructions gives you a much richer device to work with in automations.

With the ZHA quirk installed, mine exposes controls and sensors for Siren On, Alarm Duration, Alarm Light Enable, Alarm Sound Enable, Alarm Sound Types, Alarm Volume Level, Firmware, Battery, External Power, Identify, Tamper, LQI, and RSSI. Being able to control the sound and strobe separately is particularly useful in Home Assistant. A flashing-light-only notification can be used when noise isn't appropriate, while other automations can trigger both light and sound. The siren supports adjustable alarm duration as well, which makes it much more flexible than a simple on/off alarm.

I also like the tamper detection. When I remove the siren from its wall-mount ring, the Tamper entity changes from Clear to Tampering Detected. One installation detail worth watching is that the mounting ring has a specific orientation - the "UP" marking needs to face upward for proper installation.

Power can come from the internal rechargeable battery or USB-C. A USB cable is included, but you'll need your own 5V DC, 1A power supply for continuous powered operation. The documentation mentions more than 300 days of battery operation in silent mode, although I obviously haven't owned it long enough to verify that claim myself. The installation material also appeared to mention removing a battery insulator, but I couldn't find one on mine; after charging, the battery was ready to go.

The hardware itself looks good and feels well constructed, and this fills what has been a noticeable hole in Zigbee options for my Home Assistant setup. Just make sure ZHA users follow the documentation and install the supplied quirk rather than stopping with the basic pairing experience. For anyone building Home Assistant automations who wants a genuinely loud Zigbee siren, a bright visual alert, or both under program control, this is a very capable little device.

0:12

Sonoff does not disappoint.

I can only say that Sonoff hasn't disappointed me in the 7 years I've been using the brand.

This siren was something that was desperately needed, and it's finally here and available. It's perfect, and I recommend it 100%.

Good Start, Can Use Improvement

This device was just released today, so a lack of some features can be forgiven. The build quality is decent, and the speaker can get pretty loud. The lights, however, aren't particularly bright. The battery is also built-in and not user replaceable, although it can probably be swapped out pretty easily by taking out the two rear screws.

I currently have it connected to Home Assistant via Zigbee2MQTT, using a SONOFF dongle. It was easy to pair, and connected without issue. What I would like to see in future firmware updates is the ability to set the volume to a numerical value (instead of choosing between four pre-set values), the ability to add custom sounds, and options for different light patterns. Currently, the light can either be disabled or enabled. Brightness, pattern, and flash speed cannot be adjusted.

The tamper status works by detecting if the siren has been removed from the wall mount. It would be nice if there was also an option to send a tamper alert if the USB cable is disconnected.

Either way, it is good to see a Zigbee siren in a market where most of them are Z-Wave. With some additional software features, this has the potential to be an excellent siren.