Features: Wireless Headset Microphone/Receiver: having low battery indication and low battery shutdown function. A/B channel will avoid the distraction of the same frequency by changing frequency when using the same frequency. Adopting UHF Digital PCB Board: 2.5ms transfer delay, up to 30 meters operating distance, good ability for anti-interference, more reliable and stable for transmit, has clear recording effect and pure sound. Reliable Quality: ABS materials appearance, environmental protection and having damp-proof, corrosion resistance function. Carrying Convenience: mini size is portable to carry with you. Plug and Play, Strong Commonality: with 6.35mm standard audio plug that makes it suitable for loud-speaker, computer audio, pull rod audio amplifier, mixing console, etc. Specifications: Material: ABS+metal Transmitter & Receiver Channel A: 600~649MHz Transmitter & Receiver Channel B: 650~699MHz Transmitter Power Supply: Built-in 3.7V 400mAh li-polymer battery Receiver Power Supply: 1 * 3.7V 1200mA 18650 rechargeable battery Microphone Transmitted Power: 10dB Microphone Mic Type: Condenser Receiver Frequency Range: 50Hz~15KHz Receiver Power: USB5V/500mA-1A Working Distance: 30 meters Item Weight: 73g / 2.57oz Package Weight: 220g / 7.76oz Package Size: 23.5 * 18.5 * 6.5cm / 9.25 * 7.28 * 2.56in Packing List: 1 * Microphone 1 * Receiver 1 * USB Cable 1 * Manual (English)