Features: Simple and easy to use, with LED screen display. 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: 50Hz-18kHz Frequency stability: ±0.005% Signal to noise ratio: >90dB Distortion: 0.5% (1kHz) Number of channels: two channels Sensitivity: -70dB M Use distance: 50-100meters in the open area Receiver power supply: DC12V/320mA Transmitter power supply: 2 * AA battery (excluding) Transmit power: 20mW Frequency range: 200MHz-300MHz Output mode: independent and hybrid automatic selection Transmitter Size: approx. 105 * 65 * 22 mm/ 4.1 * 2.5 * 0.8 in Receiver Size: approx. 104 * 45 * 20 mm/ 4.1 * 1.8 * 0.8 in Package Weight: approx. 458 g Transmitter: Transmitter battery: 2 * AA (excluding) Frequency stability: ±0.005% Carrier output power: ≤30mW Spurious emission suppression: >40dB Modulation method: vhf Maximum modulation: ±75KHz Pickup mode: (capacitive) (LWM-6188/C) Receiver: Receive sensitivity: <2μV Image rejection: >40dB Audio output impedance: 600Ω Audio output level: 0-0.5V Use power: AC 220-240V 50/60Hz Power consumption: 1W Package list: 2 x Transmitter 1 x Receiver 2 x Microphone 1 x Adapter Connector 1 x USB Cable 1 x English Manual .