Also a popular idea for access to the rear of jewerly stores. A rim
cylinder set so that one key will turn right and a different key will
turn left. A small micro switch is attached to the back of the
cylinder and the button portion rides above the plug retaining cap.
The cap is thinned on one side so the button is always extended when
the key is turned one way. If it is turned the other direction, the
button is pushed which sets off a silent alarm.
- posted 18 years ago