The AKG WMS 40 Minisystem includes an SR 40 MINI receiver, a PT 40 MINI pocket transmitter, a MKG L instrument cable, a universal power supply with US/UK/EU adapter, and one AA size dry battery. The SR 40 Mini receiver provides three status LEDs indicating ON/OFF status, received signal strength (RF OK), and audio clipping (AF CLIP). The VOLUME control sets the level at the ¼" output jack. The supplied switched mode power supply operates on any AC voltage from 110 to 240 VAC and includes EU, UK, and US adapters. The PT 40 Mini bodypack is probably the smallest and lightest transmitter in its class. A reliable mini XLR output allows you to connect every compatible AKG miniature microphone. Battery life of the transmitter is 30 hours from a single AA battery, reducing the need to constantly replace batteries, saving some real money in the long run.