The CF-416A is a Comet duplexer for transmitting / receiving in both 144 and 430 MHz ranges in the same time. Combined hi grade filters work for preventing TVI. The isolation between the two connectors (PL/PL) is better than 60dB. In case of using CF-416A for one frequency, the other end can be remain open, but an additional Dummy Load would be better. We can use it to combine two transceivers to the same antenna, or two antennas to the same coaxial cable.