This is a dual channel transmitter that activates after entering a suitable combination. The units are designed for indoor or outdoor installation, providing high security as the transmitted code changes with each transmission session. Estimated transmission range is 200 meters in open space and 35 meters indoors. Battery life is estimated to last up to 2 years based on 10 transmissions per day. Power: 6 Volt DC 2 PCS CR2032 Li battery Battery life: 2 years (4 operations per day) Frequency: 433.92 MHz +/- 75 KHz Transmitter power: 1 mW Data format: standard Operating temperature: -20C to +55C Password number: 0-8 Waterproof rating: 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 and different displays may cause the color of the item in the picture to vary slightly from the actual product. Measurement allowed error is +/- 1-3 cm.