Over-the-ear headset with noise-canceling microphone offers superior sound and an innovative three-point design that provides ultimate stability with supports behind, on top of, and on the ear. Design offers four user-selectable, earbud sizes and adjustable receiver arm for a precise fit. Quick Disconnect lets you leave your desk without removing the headset or disconnecting the caller. Headset can be worn on either ear and is exceptionally lightweight at less than 1/2 oz. Headset requires Vista M22 adapter to connect to phone or DA45 USB-to-headset audio processor to connect to PC.