The new IEM600 offers 16 switchable UHF frequencies and has been updated with a high quality input stage for better dynamics and sound performance. The extremely strong and lightweight receiver, the IEM600 R, is equipped with a 3.5mm mini jack-socket for the earphones, a volume control and an on/off/mute button with LED indication. The separate on/off button allows switching without changing the volume. Up to four IEM600 can be run in parallel. To install the transmitter into a rack two different rack adaptors are being provided.. Recommended for use with the IEM600 are the MPH-100 MK III headphones.