The CVM-WM100 PLUS is a wireless microphone system with a dual-transmitter which is triggered by one receiver. It is powered by two AA batteries and supports the use of an external battery via a Micro USB port on the receiver. It utilizes UHF wireless FM technology, includes a high-resolution lattice LCD screen, has 16 levels of gain adjustment, includes an integrated low cut filter, Auto IR channel match, Stereo/Mono switchable audio modes, RF Signal strength adjustment, MIC/LINE Input dual selection, Power monitoring at the receiver end, Sound pickup dynamic display, Backlight Adjustment and other functions. FeaturesTwo Transmitters Work Simultaneously With One ReceiverWorking Distance Up To 328ftAA Batteries and External Charging SupportReal-Time Monitoring16 Levels of Gain AdjustmentHigh-Resolution Lattice LCD DisplaySpecificationsLavalier Transmitter: Greater Than 0.5%Channels Lavalier Transmitter: 48Channels Lavalier Recevier: 48Stray Radiation: Lesser Than 60 dBOperating Temperature: 32 to 122 deg FWeight: 1 lbs