Shure AD4Q 4-Channel Axient Digital Wireless Receiver | Frequency: B (606-810 MHz), Accessories: US Power SupplySetting the standard in spectral efficiency, the ADQD from Shure is a quad channel receiver that offers reliable wireless audio in even the most challenging environments. The ADQD is set apart by its Quadversity mode, which extends antenna coverage and improves RF signal to noise. Part of the Axient Digital Wireless Systems series, this receiver is compatible with AD and ADX series transmitters. This receiver boasts all the bells and whistles you need