Mono Headset with unidirectional noise canceling mic: The noise canceling microphone is designed for reliable vocal use in many noisy environments, keeping one ear free. One size fits all: with an adjustable headband, easy to clean soft leatherette ear cushion, This on-ear headphone can be adjusted for ultra comfortable fit on most any head size. Single plug - Plus PC Y adapter: uses a single (4 barrel) 3. 5mm CTIA compatible plug, perfect for use on today's devices. Includes a PC Y adapter with two 3. 5mm plugs (one for the microphone, one for the headphones), for older computers that require separate connections for each.