The MFJ-1700C is for folks that have multiple antennas and multiple receivers (or transceivers)! It can handle up to six radios and six antennas. The selection of the antenna and selection of the radio is made via two rotary switches. The MFJ-1700C has four mounting holes for desk or wall. It may be used for transmitting up to 2000 watts single sideband or 1000 watts Morse code at 50 to 75 ohms. SO-239 type jacks. Black aluminum. 4.5 x 7 x 3 inches. Now with built-in surge protection.