System 20 PRO 4-channel receiverMain Features:Half-rack chassis capable of receiving up to four transmittersEach receiver channel can be paired with up to four transmitters, allowing users to instantly switch between different transmitter configurationsSwitch between Standard (10 channels) and HD (20 channels) modesReceiver units can be docked in the chassis or mounted remotely (up to 328 feet away) viaEthernet cable for added versatilityUp to five chassis can be linked and used simultaneouslyMonitor transmitter status, audio level, remaining battery time, and other information in A-T Wireless ManagerAuto-lock function prevents unintended operationsSpecifications:Operating Frequencies: 2,402 to 2,480 MHzDynamic Range: 120 dB (A-weighted), typicalTotal Harmonic Distortion: < 0.05%, typicalMaximum Simultaneous Use (recommended):-Standard: 10 channels-HD mode: 20 channelsIt depends on the region and environment.System Frequency Response: 20 to 20,000 HzVaries depending on the microphone to be installed.