STEREO VOICE & ADVANCED BLUETOOTH 4.1 TECHNOLOGY QCY Q29 WIRELESS EARBUD BUILT BLUETOOTH V4.1, WHICH PROVIDES AN INCREDIBLE AND STEREO SOUND, GREAT NOISE CANCELING FUNCTION ALLOWS YOU TO JUST FOCUS ON YOUR FAVORITE MUSIC WHEREVER YOU AREAND CLEAR PHONE CALLS ARE ALSO SUPPORTED WITH BUILT-IN MICROPHONE.220 MAH BATTERY PROVIDE EXTEND 12 HOURS MUSIC AND TALKING TIME. 45 MAH BATTERY FOR EACH EARBUD. NEVER WORRY ABOUT LOW BATTERY WHEN YOU ARE IN SAY GOOD BYE TO LINE LIMITED MOST POPULAR DUAL WIRELESS EARBUD,FASHIONABLE AND BLACK SENTIENCE TECHNOLOGY DESIGN.NO LINE LIMITED,SHARING THE MUSIC OR MOVIE VOICE WITH YOUR WIFE, CHILDREN, PARENTS OR YOUR FRIENDS. WIRELESS CONNECT RANGE UP TO 10 METERS (33FT).COMFORTABLE AND SECURE FIT BRING S/M/L THREE SIZE EAR TIPS, SUIT FOR MOST PEOPLES EAR.NO PAINS WHEN YOU PUT THIS EARBUD IN YOUR EAR FOR 2-3 HOURS. KIND NOTICE: QCY Q29 BLUETOOTH HEADPHONES SUIT FOR INDOOR RELAXING,