Cyber Acoustics Stereo Headset, headphone with microphone, great for K12 School Classroom and Education (AC-201) STEREO HEADSET WITH UNIDIRECTIONAL NOISE CANCELING MIC: The noise canceling microphone is designed for reliable testing, speech, and other vocal use, in less than ideal environments. ONE SIZE FITS ALL: With an adjustable headband, easy to clean soft leatherette ear cushions, these on-ear headphones can be adjusted for ultra comfortable fit on most any head size. DUAL PLUGS - EASY TO USE: Uses two 3.5mm plugs, one for the microphone, one for the headphones, perfect for computers with separate connections for each. DURABLE DESIGN: These headsets are hardwearing and long lasting, while light weight, which is vital when being frequently used in schools, classrooms, and businesses. QUALITY GUARANTEED: Includes 1 year hassle-free warranty. Connectivity technology : Wired 30 mm dynamic drivers, frequency for headset 20-20KHz and Microphone 100-16KHz