Features: Wide Application -- Suitable for all gate openers. Can be used extensively for access control systems, parking lots, defense walls, doors, and windows, balconies, garages, corridors, and other places. Perfect to install for security systems in schools, office buildings, hospitals, home gardens, etc. Stable Signal Transmission -- High-performance infrared transmitter and receiver. The transmitter creates a reliable and invisible infrared beam up to 20 meters. When the infrared beam is interrupted, the relay will send an output signal. Waterproof & UV-resistant -- Fully sealed waterproof and dustproof egg-shaped protective cover, sunshade cover, allowing it to work in harsh environments. Easy installation. Reliable to use -- Equipped with advanced security technology that ensures multiple protections and security. Infrared photocell beam will make the gate stop or reverse automatically when encountering obstacles to protect your safety and property. Easy to install -- Install each pair on opposite positions. There is an infrared area between these two detector parts. When someone passes through the infrared area, the detector will send an alarm signal to the security guard (not included here). Specifications: Color: Black Material: PC (Waterproof, UV-resistant) Detection area: Outdoor: 20m; Indoor: 30m Detection speed: 30ms Infrared frequency: 1.92Khz Wavelength: 940nm Operating voltage: DC 12-24V Input current: RX 15mA - TX 30mA Relay output: A1 36W Article size: 76*49.2*21.6mm/3.0*1.9*0.9in Packaging list: 1 * Pair infrared sensors (transmitter and receiver)