Amazon.comThe Plantronics S12 Telephone Headset System offers hands-free convenience and comfort and 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.With a 5.75-by-9.0-inch footprint, the S12 fits easily onto available desktop space, while a headset stand provides a convenient resting place for the headset.Clean Design and Hands-Free ConvenienceThe S12 is a complete telephone headset solution for those looking for hands-free convenience with clean, uncluttered design. S12 is a corded headset that includes a Firefly in-use indicator headset and a stylish adapter which connects to your telephone. The S12 is compatible with the majority of corded business telephones through the use of a slide switch and microphone level controls. It's compatible with both single and multi-line phones for application flexibility.The S12 fits easily onto available desktop space with convenient headset stand.View largerVolume and mute controls on the S12 keep you in control of the audio during the call. An extended boom and noise-canceling microphone filter out background sounds for heightened speech clarity. Get the audio quality of corded handsets while keeping your hands free to type or take notes. Exclusive Firefly In-Use LED IndicatorThe Firefly in-use indicator headset is unique to Plantronics and features a bright LED that flashes when you are using the headset to make a telephone call. It is prominently situated near the headset microphone to ensure your colleagues are aware that you are using the telephone. Two Wearing Styles for Total ComfortThe headset features two wearing styles: a conformable earloop and an adjustable headband, with a behind-the-head neckband as an optional extra. Enjoy the convenience of an over-the-ear design or the stability of an over the head design for maximum flexibility. Add Hands-Free Capability to Any Desk PhoneThe S12's adapter connects to your telephone. The adapter includes features such as headset/handset switch, volume control and mute control for your listening comfort. The adapter can either be powered using batteries or by an optional power supply unit.Technical Specifications Weight: Over-the-head, 41 grams; Over-the-ear, 18 grams Frequency Range: Transmit, 100 to 4000Hz; Receive, 200 to 4000Hz Noise Cancellation: 10dB Acoustic Limit: 24dBPa What's in the BoxHeadset, amplifier, AC power adapter, cord (phone to amplifier)Product DescriptionPlantronics 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 your customers are on the phone.From the ManufacturerPlantronics S12 Telephone Headset System offers hands-free convenience and comfort. Includes a two-in-one 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.