AGO-80 transmitter is using 1pc 3.6V battery; battery not included in the package; Product Name Battery Infrared Sensor AGO-70 Function Widely used for automatic garage door opener gates windows for safety Package White box, yellow box, color box optional Working voltage Transmitter : 3V (2PCS AAA battery 1.5V LR03), Receiver : 12-24V DC Working current Transmitter 12m (range can be reduced to 30% in bad weather conditions : for rain ,dust ,etc) Relay contact loading capacity 1A/30VDC Size 100*40*35mm Operating temperature -10℃ to +70℃     Product Name Battery Infrared Sensor Model name  AGO-80 Function Widely used for automatic garage door opener gates windows for safety Package White box, yellow box, color box optional Working voltage Transmitter : 3.6V battery, Receiver : 12-24V DC Working current Transmitter < 100µA, Receiver < 30mA (24V DC) Photocell wavelength 940nm Angle of emission ≤±5° Receiving range 20m   Relay contact loading capacity 1A/30VDC Size 100*40*35mm Operating temperature -10℃ to +70℃   1.Install each pair at the opposite positions.Then there is a infrared area between these two detector parts. When someone passes the infrared region, the detector will send alarm signal to the security alarm host (which not included here). 2. Install Distance(Max.)in the above chart means the maximum install distance between the two detector parts. 3. Great to be installed for security system in school, office building, hosipital, home yard, etc. 4. Detecting range can be reduced to 30% in bad weather conditions, like rain, dust, etc. 5. English Usage Manual included in the pack. It will give you detailed instructions.