Receiver-Transmitter, RT-178/ARC-27 UHF Aircraft Transceiver. Frequency Range 225-399.9 MHz, A2, A3 emissions. Power output: 9 watts. 18 preset frequencies on any one of 1750 frequency channels. Transmitter may be tone modulated at 1020 Hz for emergency or direction finding purposes. One guard channel in the 238- 249 MHz range can be simultaneously monitored. The Radio is supplied in good condition Grade 3 Un-Tested.