This is a dual channel transmitters that are activated only after having entered a Suitable combination.<br> The units are designed for installation in indoor or outdoor locations that ensures the utmost security because the transmitted code is changed at each transmission session.<br> The estimated transmission range is 200 m in open space and 35m indoors .<br> The units are designed to battery life equivalent to an estimated 2 years of oper- considering 10 transmissions/day.<br> Power:6Volt DC<br> 2PCS CR2032 Li battery<br> Battery life:2 years(4 times operation every day)<br> Frequency:433.92MHz+/-75KHz<br> Transmitter power:1Mw<br> Data format:standard<br> Work temp:-20~+55 centidegree<br> Password number:0-8<br> Water proof level:IP54<br> Material:Plastic + Metal<br> colour:Black + gray<br> Package Contents:<br> 1 x Keypad<br> 1 x English Manual<br> Only the above package content, other products are not included.<br> Note: Light 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 +/- 1-3cm.