Cyber Acoustics Mono Headset, headphone with microphone, great for K12 School Classroom and Education (AC-104) 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. Durable design: this headset is long lasting, light weight, and is ideal for enterprise, office, business, mobile, classroom and home use. Quality guaranteed: includes 1 year hassle-free warranty.