This is a dual channel transmitter that activates only after entering a suitable combination. The units are designed for installation in indoor or outdoor locations, 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. The units are designed to ensure battery life equivalent to approximately 2 years of operation with 10 transmissions per day. Power: 6 Volt DC Battery: 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: Lighting and different displays may cause slight color differences between the item in the picture and the actual item. Measurement allows an error of +/- 1-3 cm.