SupraPlus Monaural Headset offers enhanced receive-side audio quality, intelligent flexible boom, bendable noise-canceling microphone and all-day wearing comfort. Comfortable, lightweight design includes a lightweight flexible cable, adjustable headband, foam ear cushion, and comfort T-pad. Quick call feature allows the headband to twist out of the way for convenient quick-call pickup. Convenient Quick Disconnect feature lets you walk away from your phone while still wearing your headset. Headset delivers the highest level of audio performance, even in noisy environments, heightened speech clarity and lifelike fidelity. Noise-canceling microphone filters out excessive background sound. Designed for over-the-head comfort (monaural). Compatible with Plantronics amplifiers and USB-to-headset adapters. Requires amplifier (PLN M22) (sold separately), which protects from loud noises, reduces echoes and background noise, and equalizes call volume.