UL listed infrared wireless microphone system. Included in the combo are 1 CRS201AMPMIX with 2 IR sensors, 2 handheld microphones, 2 rechargeable batteries, 2 handheld microphone chargers, 2 each 1/4 inch Phono jack to 3.5 mini adapters, 2 keys and 4 black P5278 loudspeakers, sold as combo. 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. The CRS201-H can simultaneously control two infrared wireless microphones, and each device can adjust its volume by independent controls to obtain the best audio effects for each individual room layout.