D2 Professional 4-Channel UHF Wireless Conference Microphone System 6.35mm & XLR Outputs Dual Antenna with Rack-Mount Receiver 4 Desktop Mics Features: This wireless microphone system includes 4 desktop conference microphones and 1 rack mountable receiver unit, perfect for conference, public speaking, teaching, etc. Adopts UHF frequency band to avoid interference; 4 channels and dual antenna design ensure clear and stable signal transmission. Each conference microphone has its own volume control knob on the receiver unit for adjusting the volume of the microphone separately to get desired vocal volume. The receiver has a 6.35mm audio mixing output to connect to speaker, and 4 balance XLR outputs for long distance connection to reduce the noise. The microphones and receiver both have LCD display showing the working information, which is helpful for you e and adjust the microphone system. Specifications: --Receiver Oscillation Mode: Quartz Controlled Fixed Frequency Stability : 10PPM Sensitivity: 2uV at sinad=12dB Max. Deviation Range: 50KHz S/N Ratio: > 103dB T.H.D.: < 0.5% at 1KHz Image Rejection: 85dB typical Spurious Rejection: 75dB typical Frequency Response: 50Hz-16Khz Power Supply: DC 12-16V 500mA Power Adapter(included) Power Adapter: 100-240V US/ EU plug(optional) Item Size: 48 * 22.5 * 4.5cm / 19 * 8.9 * 1.8in Item Weight: 2350g / 5.2lbs --Microphone Power: < 30mW Spurious Emission: < 40dB Power Supply: 2 * AA Batteries(not included) Item Size: 15.5 * 14.5 * 5cm / 6.1 * 5.7 * 2in Item Weight: 700g / 1.5lbs Package Size: 54 * 37 * 13.5cm / 21.3 * 14.6 * 5.3in Package Weight: 6225g / 13.7lbs Note: You will need an extra speaker or amplifier to connecting with the receiver to make the sound working. The batteries for microphones are not included. Package List: 1 * Receiver 4 * Microphones 4 * Microphone Bases 4 * Microphone Windscreen 2 * Antennas 2 * Mini Wrenches 1 * Audio Cable 1 * Power Adapter 1 * User Manual(English)