Up to two SU20 systems can be used together — providing four wireless channels working at once. Use Up to 4 Mics Together : Add a second SU20 system for more channels. Chord SU20-C Key Features Housed in a tidy half-rack receiver, the SU20-C features balanced XLR outputs for each channel and a mixed unbalanced 6.3mm jack output for easy connection to your mixer, amplifier, or active speaker.
eBay