4D Professional 4 Channel UHF Wireless Handheld Microphone System 4 Microphones 1 Wireless Receiver 6.35mm Sound Cable LCD Display for Karaoke Family Party Presentation Performance Public Address Specifications: Model: 4D Working Frequency： 903.45~909.50 915.90~923.00 907.70~919.15 921.50~926.15 902.25~905.65 912.35~918.55 910.35~917.35 924.15~927.85 Receiver: Frequency Response: 60Hz-16KHz Signal to noise Ratio: > 103dB Working Range: 80meters(in the open area) Receiver Size: 42 * 21 * 4.5cm / 16.5 * 8.3 * 1.8in Receiver Weight: 1748g / 61.6oz Microphone: High Frequency Output: 30mW(Maximum) Power Supply(Single): 2 * AA Batteries(not included) Microphone Size(Single): 26 * 5 * 5cm / 10.2 * 2 * 2in Microphone Weight(Single): 341g / 12oz