Bluetooth V4.1 EDR Class 2 device Black or White Lightweight Wireless Moon Shape Sweatproof Earbuds CVC6.0 Dual Mic Noise Echo Reduction Headset 500 Hours Standby Time Speaker Frequency 300Hz-400Hz Enjoy your workout, burn the calories break a sweat with no worries about perspiring or destroying your headset because there sweat-proof so go ahead feel the burn with the 0.3 oz. featherweight wireless sporting headphones. High quality stereo built in APT-X technology reproduces CD quality sound over a Bluetooth 4.1 + EDR Class 2 that connects two devices at the same time with 9mm high fidelity audio and earplugs for an enhanced life like clear sound. Experience the unique moon shape earbuds that gives a snug fit within the ear canal, plus an around the neckband for sleek all day comfort. Receive phone calls; talk with a vibrant voice that has CVC 6.0 dual microphone noise and echo deduction. Volume control keys for music and songs. Surround type design is convenient to carry, more at ease than other brands.