UL listed amp mixer wireless module no microphones. Included in the combo are 1 CRS201AMPMIX, 2 each IR sensors, 2 ea 1/4 inch phono jack to 3.5 mini adapters, 2 keys, sold as combo. The CRS201is infrared wireless microphone system (UL listed) is ideal for classrooms, boardrooms, computer training rooms and hotel meeting rooms. The slim, fully lockable, wall-mounted infrared receiver/amplifier/mixer accepts three different line level inputs. Because the CRS201 is wall-mounted, there are no freestanding or rack-mounted components to take up closet space or be knocked off a shelf, and no unsightly tangle of wires. The CRS201 system can simultaneously control two included infrared wireless microphones, and each device can adjust its volume by independent controls to obtain the best audio effects for each individual room layout.