Plantronics S12 Telephone Headset System offers hands-free convenience and comfort. Includes a 2-in-1 convertible headset for over-the-head stability or over-the-ear convenience, a noise-canceling microphone for superior sound clarity and the Firefly in-use indicator light that lets others know you are on the phone. Features - In-use indicator lets others know when you're on the phone - Noise-canceling microphone reduces background noise - Headset can be configured over-the-head or over-the-ear