Sennheiser SR IEM G4 GB-Band, Evolution Wireless In Ear System Transmitter (SR IEM G4), up to 1680 frequencies in 42 MHz bandwidth, 20 channel banks with each upt to 12 Presets, up to 16 compatible systems, audio frequnencie range 25 - 15.000 Hz, infra red data and frequency transmission, autotune to find free frequencies, LCD Display with NF and channel, switchable transmitted power 10/30/50 mW, WSM-Support (Ethernet-connecor for Frequency Management), adjustable 6,3mm headphones connector on the receiver, 1 BNC antenna connector, 2x jack/XLR female balanced combi connectors, powersupply 10,5 - 16 V DC, incl. powersupply NT 2-3 UK, Rackkit GA 3 and Antenna, frequency range GB-Band 606 - 648 MHz. Please note: Due to every country having different regulations, you may need to Contact your local licensing authorities before using a wireless system.