The Sennheiser SD-PRO2-ML is a dual-sided DECT headset with Ultra Noise Canceling Microphone optimized for Microsoft Lync for your desk phone and softphone. Exceptional voice clarity and wideband sound. Fabulous range of up to 180 feet and up to 590 feet line of site, . Recharges 50% of the battery in 20 minutes, Mute and Volume on Headset, 8 hours of Wideband TalkTime or 12 hours narrowband. Great Professional Headset!