The AKG RMU4X PRO is a professional rackmount kit including a long and a short rack bracket, a coupling plate, two antenna covers, two antenna front mount cables, two antenna splitter cables and spare screws. The included rack brackets are compatible with AKG WMS420, WMS450 and WMS470 wireless receivers. Each rack mount kit includes everything needed to mount ONE receiver. Two rack mount kits are required to mount two receivers. The RMU4X PRO allows you to mount your receiver into a 19” rack and to mount the antennas to the front plate.