5Pcs SFM-27 DC 3-24V Electronic Buzzer Alarm Sounder Continuous Sound Beep (Pack of 5) CYT1083

I used one of these to connect to a keyless entry system of a car so that it makes a subtle beep when you press the unlock or lock button. It makes a nice beep sound with 12v of power. I was worried it would be too loud or too quiet for the application I was using it for, but it turned out to be just perfect. I did notice that all 5 of the piezo buzzers make a slightly different tone with the same amount of power, which could be good if you wanted a slightly lower or higher tone in the beep.