This is a dual-channel transmitter that is activated only after entering an appropriate combination. The units are designed for indoor or outdoor installation, ensuring maximum security as the transmitted code changes with each transmission. The estimated transmission range is 200 m in open space and 35 m indoors. The units are designed for a battery life equivalent to approximately 2 years of operation - considering 10 transmissions/day. Power: 6 Volt DC 2 pcs CR2032 Li-battery Battery life: 2 years (4 times use every day) Frequency: 433.92MHz +/- 75KHz Transmit power: 1Mw Data format: standard Working temperature: -20~+55 centigrade Password number: 0-8 Waterproof level: IP54 Material: Plastic + Metal Color: Black + gray Package contents: 1 x Keypad 1 x English manual Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.