2V 3V 5V 6V 9V 12V DC Piezo Electronic Buzzer Very Load Alarm Electric Security Siren Horn 120dB@12VDC

I have a stand alone remote controlled motion alarm. I plugged this siren in and mounted it in the next room. Installation done. This little siren is loud. It is a different pitch than my other alarm and between the two it is uncomfortably loud. I definitely recommend this siren if you have a device that it can plug into.All the wifi smart security system cameras are great for helping the cops find the perps after your house has been robbed or you have been killed. A few now have sirens in addition to all their cameras. Did you know that you can buy wifi jammers on the inter net that nullify your wifi security system? Buy a couple of battery operated or battery backup stand alone non wifi old school motion alarms for the rooms where your outside doors are. Even high tech crooks don't like loud alarm noise.

I bought this as part of a DIY FloodLight system that I'm building. This will be the siren that I will be able to trigger, either by motion or remotely. I had no idea what to expect really. I received it and took it out of the box and was impressed with the build quality - I was expecting something much cheaper feeling. For the price it's actually well constructed. Next, being impatient, I just grabbed a used AA battery (maybe it had ~1.2V charge on it) and just connected both ends of the siren to it (after snipping off the 3.5mm jack connector - save it for later if I need it). Even at 1.2V it had decent volume and was good to alert someone indoors in the same vicinity. Probably not going to hear it out doors but I was impressed that even at 1.2V it was a respectable "noise" level. I then got out my power generator and connected it up and started cranking the voltage up - after around 2.2V it became VERY loud. I increased it to 3.3V (which would be the output level of my esp8266 mcu) and it was VERY LOUD, almost to the point where i needed some ear protection. My wife started nodding - yeah, that's definitely going to frighten away anyone nosing around our front porch. I stopped there because I was indoors. I'm shuddering to think (in a good way) how loud this will get at 5V, or even the full 12V. So very pleased with this unit, so pleased that right after this review I'm going to buy another 1-2 units. It's nice to know I could potentially power it from a single AA battery all the way up to a full 12V. Highly recommend!

I don't know how they can get such a loud sound out of such a small package but this thing delivers.Be very careful when testing this, it is loud enough to damage your hearing when close to it. Makes an excellent burglar alarm, should drive them away. Put one of these in every room of your house and they won't be able to tolerate being in there.I almost took off a star because of the plug and no documentation. But simplest is to just cut it off - however that would prevent you from returning it if you decided it wasn't loud enough ha ha. Anyway I found that tip is positive and the sleeve is negative. It survived having the voltage reversed.I only tested it at 12 volts. If it is too loud for your needs then you should be able to reduce the voltage for less volume.

As I stated above, I found some of the comments funny but most of them appear to be spot on. I am using this little thing as an added sound effect to my pipe organ (yes, pipe organ!) For that reason I need to limit the power to 5v dc. Yes it's plenty loud if not annoying at 5v never mind 12 which I do not plan on ever using. Again all depends on where it gets situated and installed.

We love these! We had family friends experience a water leak and a great deal of damage to their house. We bought these along with a adapter to convert to a traditional outlet plug. We use them with Wyze leak sensors and Wyze smart plugs. Now if there is a detected leak under the kids sinks, sump pump, toilet, kitchen sink, hot water heater, etc the a Wyze app rule turns on the plug for one minute and activates this very loud siren to alert us to the leak! I’m sure there are many other uses too that you can think of! If it is too loud you can dampen with a washcloth, or about five Kleenex or a few paper towels over the top secured with rubber-band!

I paired this with a cheap wifi switch and a 12-volt adapter for use as a siren with my Home Assistant setup. It's ear-splittingly loud. I love it.

I'm using this with a float switch on my water heater drip pan to alert if the pan begins to fill with water. I have an AC to DC power supply set at 4.5 volts powering this alarm, and it is painfully loud even at only 4.5 volts. This is an inexpensive device and seems pretty lightweight so I don't know how long it may last. Perhaps the lower voltage will extend its life.

Worked once then failed. What else is there to say?