This product is a professional wireless microphone system. DSP2020 is the wireless microphone receiver, which can be combined with several kinds of transmitters to form a wireless microphone system. The combination set includes DSP2020A (Hand-held+Headset Wireless MIC+Receiver) Wireless Microphone Set and DSP2020B (Clip+Headset Wireless MIC+Receiver) Wireless Microphone Set. Application scopes: conference hall, teaching lectures, home entertainment, etc.