Feature: 1. High Sensitivity: The lens type optical element strengthens the beam intensity, has good immunity to false alarms caused by rain, snow, fog, etc., highly convenient to use. 2. Low Battery Reminder: When the battery is low, the red LED on the transmitter side will flash, and the receiver's buzzer will sound every second to remind you to replace the battery in time. 3. Wide Applications: Provides invisible infrared beams for automation applications such as sliding and swinging doors, garage doors and security applications, outdoor or indoor fencing, etc. 4. Waterproof Protection: Infrared gate beam sensor is IP55 waterproof, can be installed indoors or outdoors, small size, easy to install, does not affect the normal function of your device. 5. Durable Structure: Infrared gate beam detector is made from superior ABS, wear resistant and durable, the transmitter is powered by 2PCS AA batteries (not included), and the long life can reach about 2 years. Specification: Item Type: Infrared Gate Beam Sensor Material: ABS Application: Home security, access control system Working Voltage: Receiver: 12-36VDC Transmitter: 3V (2PCS AA battery, NOT included) Installation Environment: Indoor, outdoor Detection Distance: Approx. 15m / 16.4yd Alarm Time: 3s, 5s, 10s adjustable Alarm Output: Relay contact output NC, NO Contact Capacity: 30V DC 3A maximum 250V AC 3A maximum Battery Life: About 2 years Wavelength: 940nm Modulation Frequency: Pulse Waterproof Grade: IP55 Single Product Size: Approx. 136x54x32mm/5.4x2.1x1.3in §§ Package List: 1 x Transmitter 1 x Receiver 4 x Screw 4 x Expansion Tube 1 x Manual How To Use 1. The transmitter and receiver are installed at a distance of 30 cm from the ground, and they are on the same level. 2. Align the beam, after the receiver is powered on, when it receives the signal from the transmitter, the buzzer will beep for 5 seconds, and the blue LED light will flash, then the light will turn on.