A compact entry warning system is designed for use in shops, restaurants, doctors and dentist surgeries etc. to alert you to the entry of customers and visitors. The system consists of a send/receive unit which transmits an IR beam across the doorway onto a prismatic reflector mounted on the opposite side. The beam is reflected back to the receiver to complete the circuit. When a person walks through the beam, the circuit is interrupted and this causes the alarm to sound an audible warning. The warning buzzer can be mounted in any suitable location. Mains plugpack and mounting hardware included. Specifications: Effective range 0.5 - 6 metres Voltage 240Vmains through 9 volt adaptor Transmitter/Receiver size 70(H) x 60(W) x 30(D)mm Reflector diameter 84mm Packaged Volume 1.376L Packaged Weight 0.517kg Packaged Length 16cm Packaged Width 10cm Packaged Height 8.6cm