The Model XT-4 4-Channel Stationary Mid-range Transmitter is designed for use in various wireless remote control applications. When triggered with an external switch, the Model XT-4 transmitter will send a 10 watt, 27.255 MHz, digital encoded, FSK modulated, signal to its companion receiver. The receiver will verify the digital code, activate its output, and trigger the remote device. Up to 10 miles of line-of-sight range, RF transmit LED, Accepts four N/O or N/C inputs, Complete RF supervision, field enabled, Fully supervised (loop status, low battery, link integrity). c/w Installation Manual. $200-OBO.