Featuresr comfortable ergonomic design lightweight and slimr advanced csr bluetooth 40 technology receiver range can up to 20 meters without obstructionr 40 mm drivers for excellent bass precise treble and clear mid tones gives you a premium soundr 350mah built in lithium ion rechargeable battery enjoy 10 hours of uninterrupted music podcasts phone calls and movies before the next charger on board controls you can control your music quickly and easilyr equipped a 35mm stereo co