Wireless hand held microphone. Cardioid polar diagram. Frequency band 863-865 MHz (UHF). Selection of up to 16 channels (8 simultaneous). Frequency response 50 to 16,000 Hz. Carrier power 20 mW. PLL modulation system. Power 2 x AA batteries. Indicator of operation, channel, and low battery. Compatible with receivers US-902DC and US-8001DC. OPTIMUS model ref. MH-850C.