Sennheiser Presence Business (506066) - Dual Connectivity, Single-Sided Bluetooth Headset for Mobile Device Connection, with USB Dongle (Black) Mobile Device Connection: For those who simply need an excellent communication solution in the office, in the car, and outdoors Improved Flexibility: Connects to two mobile phones to allow for seamless transitions between calls Optimized Speech Clarity: Unique SpeakFocus technology with three digital microphones enhances voice clarity in all sound environments and provides the user with consistently clear sound Advanced Own-Voice Detection Technology: When you are speaking, an own-voice-detector detects your voice and optimizes speech intelligibility as well as reduces background noise for your listener Equipped: Comes included with a Car Charger, USB Charging Cable, USB Dongle, Ear Hook, all designed to ensure you are ready, no matter where you are 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 of your office headset Extended Talk-time: Presence delivers up to 10 hours call time between charges. Choice of Wearing Styles: Three-in-one wearing solution for maximum comfort and convenience Wind Noise Reduction  WindSafe technology reduces wind noise in outdoor situations