“Has somebody been snooping around in your hotel safe?
I wanted a simple device that would tell me if somebody had been in my hotel safe whilst I was out on holiday, so I designed LightSafer. LightSafer is a tiny 33 x 21 mm (1.3 x 0.8 inch) gadget with PIN code entry that lets you know if somebody has been snooping around in your hotel safe (or sock drawer).
It’s completely silent. You just press the button to arm LightSafer, put it in your safe and if anybody opens the safe and fails to enter the correct PIN, the alarm LED lights. Once the alarm is triggered there is no way to turn it off. Even if the battery is removed, as soon as a new one is put in, the alarm LED lights straight back up.
Entering the correct PIN is the only way to disable the alarm.”