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.
In-use indicator lets others know when you're on the phone
OFFICE PHONES 
VoIP PRODUCTS 
When 2 or 3 handsets is enough...