Features high definition Bluetooth 4.1 wireless technology and built-in microphones. Simply pair your handheld device to enjoy dynamic stereo sound or receive hands-free calls. Has interchangeable earbud covers. Earbuds include 40 mah battery. Store earbuds in magnetic charging cradle. 230 mah lithium ion grade a non-recycled battery. Features a micro usb input (cord included). power bank output: 5 volts/1 amp. Works with most audio devices. Pairs from up to 30 feet away.