Feature: Brand New and High Quality Professional Dual Wireless Microphone System. The frequency: VHF The frequency range: 165-270 MHZ Voice Compression Directivity: Uni-directional Frequency Response: 165 to 270 MHz Output Impedance: 600 Ohm Transmitter Size: 8.5*6.5*2.5cm Receiver size: 11.7*7.8*2cm Transmitter Power: 9V Battery(not included) Receiver Power: AAA Battery x 2(not included) Output impedance: 600 ohms Use power: a 9 V battery transmitter section Effective distance is about 30 to 50 meters Connects to most audio devices that have microphone inputs. (guitar amplifier， karaoke machines， etc.)Package Content: 1X headset microphone 1X clip-on microphone 1X 6.35mm to 3.5mm AUdio Line 1X receiver transmitter and receiver(NO Retail Box. Packed Safely in Bubble Bag)