System 20 PRO handheld microphone transmitter.Main Features:Two antennas built into the transmitterHigh sound quality (24-bit/48 kHz)Compatible with NiMH batteries for all-day useSlide-to-mute switchOLED displaySpecifications: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.