The CP-PC180B is a battery-powered infrared photocell with robust shock-resistant plastic casing.
 
The transmitter operates with four AAA alkaline batteries, while the receiver can operate at 12 or 24 V ac / dc. 
 
The optical system of both the transmitter and receiver can be rotated up to 180° which allows side aiming, therefore the units do not have to be mounted face-to-face and the beam direction cannot be discerned by simple observation.
 
They are ideal for safety use on gates, roller shutters and garage doors. Detecting obstacles including vehicles and people, when the beam is broken the equipment will stop and reverse, preventing damage or injury.
 
Can also be used to activate alarms, lighting and other devices.