AKG Pro Audio WMS420 Vocal Set Band U2 Wireless Microphone System Detachable receiver antennas enable the use of professional RF accessories Patented state-of-the-art D5 dynamic capsule cuts through the mix Transmitters with charging contacts saves money in day-to-day use and preserves the environment Compatible with all AKG Micromics almost all applications can be covered Low battery warning indicator for secure operation