What a riot! I built one of these about 17 years ago as a joke. My sonic grenade has a 1/8 phono jack ‘pin’ with a green LED in the end that would light up when the main switch was switched. The main switch was covered with one of those cool aircraft switch covers. When the pin was pulled five LEDs would count down and then blast the area with a mind numbing 120dB sonic blast of pain. Everyone loved it. If only I had know that people would buy stuff like this.
This one works about the same except the only way to shut it off is to replace the pin! Sounds like a one use wonder to me, if someone used it one me I know hat I’d be pretty keen on breaking it in to little silent pieces.
[via The Red Ferret Journal]
Sonic alarm