The WMS 40 Mini Vocal / Instrumental Set Dual ensures brilliant sound and ease of use at an unbeatable price/performance ratio. Unique HDAP (High Definition Audio Performance) technology ensures the best possible, most realistic sound at any time. The SR 40 Mini2 receiver provides three status LEDs each for channels 1 and 2, 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. Each receiver comes with a universal 12-V switched mode power supply with EU, UK, and US adapters. The illuminated ON/OFF button switches both channels on and off simultaneously. The PT 40 Mini bodypack is probably the smallest and lightest transmitter in its class. A reliable mini XLR input allows you to connect every compatible AKG miniature microphone. The rugged HT 40 Mini handheld transmitter features an ON/OFF/MUTE switch and a sturdy wire-mesh cap protecting the cardioid dynamic microphone element. Battery life is the same legendary 30 hours off a single AA battery as for the standard WMS 40 models, reducing the need to replace batteries and thus saving real money in the long run.