Sennheiser SD Pro 1 (506007) - Single-Sided Dual Connectivity Wireless DECT Headset for Desk Phone & Softphone/PC Connection, Ultra Noise-Cancelling Microphone (Black) Enhanced Flexibility: This headset is designed for business professionals who communicate with a desk phone and softphone Dual Connectivity: Switch from deskphone to PC with just a touch on the base station Ultra Noise-Cancelling Microphone: Filters out all unwanted background noise for crystal-clear conversations Fluid Conferencing: Up to 4 headsets can be paired to a single DECT base station for a call, making conferencing as simple as it should be Intuitive Call Control: Answer/end a call, mute the microphone, and adjust volume directly on the headset for added simplicity ActiveGard Technology: Featuring patented hearing protection to defend against acoustic shock caused by sudden sound bursts Peace of Mind: With a 2-year warranty on all headsets (including batteries), you never have to worry about the quality if your office headset Voice Clarity: Delivers a warm and more natural sound that allows you to catch the tone of your callers voices and avoid misunderstandings All-Day Use: Designed to last a working day with extra soft leatherette ear pads and a comfortable headband for maximum wearing comfort Long-Distance Wireless Range: Extends your working range up to 590 ft. in line of sight so youre always in contact with your phone