Nady DKW DUO LT/O/P/R VHF Dual Receiver Lavaliere Microphone System Supplied with LM-14O omnidirectional lavaliere/lapel microphone Off/Standby/On switch allows convenient audio muting with the transmitter on Input level adjust Locking 3.5mm jack LED status indicator flashes once for Unit On, lights steady for low-battery alert