ITEM NAME:Wireless Mic Head-mounted Microphone with Receiver Transmitter Microphones Product Description Description: Portable Wireless Mic Head-mounted Microphone with Receiver Transmitter Microphones Features: Simple and easy to use. A wide range of device support applications, as long as the device with a microphone interface can be connected. Applicable to teaching, business promotion, stage conference training. Automatic connection, wide application, compatible with audio, amplifier, multimedia, mobile audio. The transmitter is equipped with a back clip for easy carrying. Specification: Frequency offset:  ±11kHz Frequency response: 80Hz-15kHz Frequency stability:  ±0.005% Signal to noise ratio: >60dB Distortion: 0.5% (1kHz) Sensitivity: -70dB M Use distance: 50 meters in the open area Receiver power supply: DC 5V/320mA Transmitter power supply: 2 * AA battery (excluding) Transmit power: 20mW Frequency range: 200MHz-270MHz Transmitter Size: approx. 105*65*22 mm Receiver Size: approx. 80*24*12mm Package Weight: approx. 178 g Transmitter: Transmitter battery: 2 * AA (excluding) Frequency stability:  ±0.005% Carrier output power: ≠¤30mW Spurious emission suppression: >40dB Modulation method: vhf 268.85MHz Maximum modulation:  ±75KHz Pickup mode: (capacitive) (LWM-6188/C) Note: Please allow 1-3mm differs due to manual measurement. Due to the different display and different light, the picture may not show the actual color of the item. Thanks for your understanding. Included: 1 * Transmitter 1 * USB Receiver 1 * Head-mounted Microphone 1 * 3.5mm Audio Cable 1 * 3.5mm Female to 6.35mm Male Converter 1 *  English Manual.The transmitter is equipped with a back clip for easy carrying. Transmitter Size: approx. 105 65 22 mm. Transmitter battery: 2 AA (excluding). A wide range of device support applications, as long as the device with a microphone interface can be connected.