LD Systems U305 IEM HP, In-Ear Monitoring System with Earphones, Frequency range: 584-608 MHz, 12 Selectable channels, Wireless transmission for a range of up to 100m, Up to 6 systems can be used simultaneously, Frequency range: 50 - 16,000 Hz, Stereo or mono mode, Detachable antenna with BNC connector, Bodypack has a runtime of 10 h with 2x AA batteries, Includes earphones and a 19"" rack mounting kit