Sennheiser Ek 300Iem G3 - Diversity Bodypack Receiver with IE4 Ear Buds For Wireless Monitoring - A Range (516-558 Mhz) 42 MHz bandwidth: 1680 tunable UHF frequencies for interference-free reception Enhanced frequency bank system with up to 12 compatible frequencies with automatic frequency scan that searches for available frequencies True adaptive-diversity reception for high reception quality User-friendly menu operation with auto-lock function to avoid accidental changing of settings Sturdy metal housing with illuminated graphic display