The MH4 microphone contains a high-performance condenser microphone element optimized for SSB, AM and FM use. It also has a Push-to-Talk button and two function buttons to control the transceiver from the microphone.
A: The MH4 is a direct, plug-compatible microphone to the MH2. Unlike the MH2, it is housed in a smaller form that fits into the hand easily, making it easier to store or carry.
A: The housing used for the MH3 and MH4 are the same but the connection plugs are different. For that reason, they are designed to be connected to their respective radios without an adapter cable in their native form. The enterprising ham, however, is welcome to build adapter cables.