Plantronics S11 Telephone Headset System (Certified Refurbished) This Certified Refurbished product is tested and certified by the manufacturer or by a third-party refurbisher to look & work like new, with limited to no signs of wear. The refurbishing process includes functionality testing, inspection, reconditioning and repackaging. The product ships with all relevant accessories, a minimum 90-day warranty & may arrive in a generic white or brown box.Only select sellers who maintain a high performance bar may offer Certified Refurbished products on Amazon. Volume and mute control. Volume and mute control. Over-The-Head style headset. Headset stand.