Sennheiser EW 300-2IEM G3 - In-ear Monitoring System - A-Range (516 - 558 MHz) Includes 2 each EK300 IEM G3 body pack receivers, 2 each IE4 ear buds, and 1 SR300 G3 rack-mountable stereo transmitter with GA3 rack kit. 42 MHz bandwidth: 1680 tunable UHF frequencies for interference-free reception Enhanced frequency bank system with up to 16 compatible frequencies Ethernet port for connecting to the Wireless Systems Manager (WSM) software for control via computer - this delivers a good overview of monitoring and professional data management for multi-channel systems Sturdy metal housing with illuminated graphic display