2 PCS Piezo Buzzer, Icstation Buzzer Alarm 12V Electronic Beep Buzzer 100dB Piezo Alarm Siren Continous Sound for Motorcycle Golf Cart Vehicles Car Alarm

They worked on f250 wired to key on fuse to tell when head lights were on

High pitched beep that is very loud as other reviews have stated. I tried at 24 volts and it did not seem substantially louder and almost as if it was overdriving the unit. I settled to operate it at 12 volts and did not attempt sustained operation at 24 volts. Perhaps somewhere between 12 and 24 volts could give a louder output but it was plenty loud for my needs at 12 volts. The wires are very thin to work with but nicely solder tinned at the ends for easy soldering if that is your choice of connection.

I used two of these in parallel to chase moles from my yard. Wired to a timer that provides a 15 min on cycle every hour or two. I placed them in a plastic gutter drain tube and burred for a short run in the ground. It seems to be working great when all the poison peanuts and other commercial products failed. It's only been a couple of weeks now, but if they just work for the rest of the summer I will gladly order new ones next spring. (NOTE) I was able to place these in an area upstream of the water flow in a clean-out. They don't seem suited for wet locations.

If you’re going to use this as an alarm substitute for a bmw e46, I would suggest spending a little more to get a louder buzzer or an actual siren. Sound is easily muffled by the hood, but sounds decent with the hood open.

They are about as loud as the squeal from my hearing aids - - and that's at about 36". It wouldn't wake me up if I was 6' away, and certainly won't be heard above the engine noise from my boat.

Perfect for what I needed it for loud and according to the fiance annoying.

I purchased these piezo buzzers because my truck's piezo device behind the instrument cluster died an unexplainable death. There have been many times over 10 years where I've left the lights on after getting to work. I wired the buzzer by simply using a t-tap connected to the power wire on the headlight and grounding the other side. I affixed the buzzer on the inside of my engine bay (cleaned the surface w/ a little brake cleaner) with some 3M heavy bond tape (the grey kind). Works like a charm.

Good price. Use on a Kubota RTV to signal when the hand brake is on.