Specifications Bluetooth Protocol: Bluetooth V4.2 Operating Distance: Up to 49 ft. / 15m. (open space) Earbud battery: 60 mAh Case battery: 800 mAh Case dimensions: 3.06*2*1.37 in / 91.5*51*35 mm How to Set Up: 1. Please plug units back to charging dock to activate your earphones. 2. Press the MFB (main function button) on both earbuds for about 2 seconds to turn them on. The indicator will flash red and blue. 3. Search the earbuds on your devices and you can connect each bud individually with your devices. 4. Indicator will slowly flash in blue light if paired successfully. How to Pair Into Stereo Model: 1. Turn on both earbuds. 2. Please hold the MFB on any one of them for 1s and hear a “Di†sound to enter pairing mode. Then wait about 4s and the two earbuds will connecting together automatically. If the earbuds are successfully paired, the indictor on the host earbud will flash between red and blue, and the slave earbud will flash a blue indictor every 5 seconds. 3. On your phone, search for the “ II†or "X3", and click to connect. Note: Only the host earbud will be activated in a phone call. This is for your safety when driving.