*利用锁相不技术确保发射和接收更加稳定可靠 *D为立体声；D-M为单声道 *工作频率：
40.68MHz适用于欧洲市场 49.86MHz适用于北美市场 *Use PLL technology to make sure the transmitting and receiving more reliable and stable *suitable frequency:49.86MHz(for American market)40.68MHz(for European market) *D for stereo sound,D-M for MONO sound