AKG SR470 Diversity Receiver for WMS470 Wireless (BD8 Band)The SR 470 lets you operate up to sixteen channels simultaneously within the same frequency band. You can even set up absolutely reliable systems with as many as 48 channels by using multiple frequency bands. The display backlighting changes in color to warn the user of such critical operating conditions as transmitter battery running low, audio peaks, or low RF signal strength. A line of professional accessories including the WMS 4000 antenna