Companion VHF receive converter for the Yaesu FRG-7700 communications receiver. Covers 3 bands as per title. In good working condition. Plugs into the acc and aerial connections on the 7700 receiver, Google will help in finding the manual. For airband 118.000-130.000 tune your 7700 between 18.000-30.000 MHz. For VHF 140-150 MHz ( inc 2 Mtrs), tune 20.000-30.000 Mhz. Example 145.500 = 25.500. For lowband VHF 50.000-60.000 tune 20.000-30.000 ( 6 Mtrs ). It has 3 x SO239 sockets on the back one for each band. It also has switchable attenuator, HF bypass, and a dual pre-selector.