System 20 PRO handheld microphone transmitter.Main Features:Cardioid polar patternLong-lasting internal lithium-ion batteries for all-day transmitter useSelectable mute operation (toggle, touch-to-talk, or touch-to-mute)Two LED options: standard mode and conference modeOLED displayUSB Type-C connector for charging (transmitter can be used while charging)Specifications: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.