Jabra EVOLVE 40 UC Stereo Headset for PC, Smartphone & Tablet: With remarkable noise-cancelling & HD sound. Offering top-class sound and noise-cancelling for call centres and busy offices environments the Jabra EVOLVE 40 UC stereo is a professional quality headset for businesses using Unified Communication. Boasting an intuitivebusy lightindicator to let others around you know when youre on a call and Jabras passive noise-cancellation, the EVOLVE 40 has been designed to improve your focus and concentration at work.. Ultimate noise-cancelling for professionals. The Jabra EVOLVE 40 UC has been designed for use in noisy office environments and counteracts interference from high-frequency sounds (such as co-workers talking around you) with Jabras intuitive passive-noise cancellation.. High-Definition Audio. Equipped with world-class speakers you can use the Jabra EVOLVE 40 UC stereo for both calls and music, and conveniently integrate the mic boom into the headband when not in use..