Peltor communication headsets are designed to be used with a transceiver/radio/walkie-talkie, provding hearing protection and at the same time communication capability. The headsets themselves cannot transmit or receive signals, with a few exceptions such as the LiteCom and Power Com.
The HT series ( listen-only ) can be connected to the radio directly for incoming signals. The MT series ( two-way ) headsets must be used in conjunction with a radio-specific adapter cable and then connected to the radio for reception and transmission. So it is a two-part ( HT ) or three-part ( MT ) system, as the case may be.
Purchasing of the HT headsets is easier, you just have to know the plug size, and whether you want mono or stereo. But purchasing of the MT headsets requires that you know exactly what the make and model of your existing radio is so that a specific adapter cable can be used to ensure proper functioning.
The LiteCom and the Power Com are self-contained systems that include the headset, cable, and transceiver. When you purchase these, you have no more extra parts or cables to buy. Put the batteries in and you are talking away!