The Yaesu / Vertex MH-44B4B is a hand-held Speaker Microphone that plugs into your Vertex or Yaesu Transceiver for convenient access. Now you can leave your Transceiver on your belt or place it next to you! Fits Vertex VXA-220, VXA-300, VXA-710 Transceivers, and Yaesu FTA-230, FTA-310, and FTA-720 Transceivers.