Plantronics CS351 Supra is one ear / voice tube for low noise environments (use binaural / noise cancelling for noisy offices). It is the ultimate for office-workers who spend long periods on the phone as its very very comfortable to use. SupraPlus offers outstanding sound-quality and a number of well-thought out features based on Plantronics unrivalled experience in this area.The quick pair feature is very useful and means that a compatible headset can be paired at the click of a button with a single base. This means that hot-desk or shift workers can keep their own personal headset and use it at any desk where there is a base.Features include: Extremely comfortable for all-day wearing Quick pair feature allows multiple headsets to share one base for effective hot-desking or multi-shift working DECT technology for excellent sound quality 100-metres range up to 50-metres in a typical office Up to 9 hours talk-time 50 hours standby time with fast recharge Remote call-answering when away from your telephone (HL10 Lifter required) Dedicated headset volume and mute control including on-mute indicator Quick call feature for short-call convenience IntelliStand automatically answers call when headset is picked up from base (HL10 Lifter)