UHF-550 Professional Rechargeable Dual Wireless Microphone System (300ft Range) UHF (Ultra High Frequency) wireless microphone system with noise reduction technology; Two highly sensitive microphones with LCD indicators and rechargeable battery design; Microphone and receiver channels auto-sync via infrared ray; Operating distance 300 ft (best indoor working range 200 ft, outdoor range 240 ft line-of-sight); Item comes with free battery charger and 4 AA rechargeable batteries. System designed in Japan.