Dual Ear Premium Quality Call Center Headset Headphones+Adjustable Volume + Mute Control for Polycom Soundpoint IP,Nortel Network Northern Telecom Meridian PBx Norstar NEC Mitel Dual Ear Sides Premium Quality Noise Cancelling Headset Headphone Direct Connect Over The Head Headset, No Additional Applifiers / Adapters Required Built-In volume adjustable and mute button control. Shirt clip included. Superior Quality Sound with the Flexible Adjustable Microphone Headband Style with Single Earpiece for Great Sound Quality in One Ear