With four sizes of user-selectable earbuds and an adjustable receiver arm, the TriStar headset can be custom fitted to just about anyone. Weighing under one-half ounce, this headset is a pleasure to wear. Quick Disconnect lets you walk away from your phone while wearing your headset, voice tube microphone improves clarity of speech.This complete headset is designed for the Cisco IP phones that use a power cube 7940, 7960, 7970.