Detail: 
• This is an electronic circuit that rely on the use of an invisible infrared ray for detection. 
• The circuit also provides an entry- exit delay. 
• It utilizes unseenable infrared to be a checker.
• Power supply : 12V.
• Recommended housing : FB10 for CT (control), FB17 for TX (transmitter), FB17 for RX (receiver)
• PCB dimensions : 3.4” X 2.3” for CT (control), 2.4” X 1.3” for TX (transmitter), 2.3” X 0.8” for RX (receiver)