At the heart of the 4000 Series is a rugged True Diversity half-rack receiver, the AEW-R4100, with 996 selectable channels offered in each of two available UHF bands. Receivers from both the 4000 and 5000 Series may be linked; they may be monitored by the 5000 Series system software. The included IntelliScan„¢ feature automatically determines and sets the best available frequencies on all linked receivers. Multiple system configurations are available, with handheld vocal microphone/transmitters and UniPak body-pack transmitters designed for use with lavalier, headworn and instrument microphones as well as electric guitars.