operation 5 Volume Control: Under the music or conversation mode: (1)Volume +: Press and hold "+" button, the volume will increase gradually. (2)Volume -: Press and hold "-" button, then volume will decrease gradually. Previous/next: In the state of music mode. press the "+" button shortly(about 1~2 seconds then release),then will go to previous song; if you need to go to next song, then press the "-"button shortly(about 1~2 seconds then release) Pause/Play: In the state of music mode, press the power button once towards inside, the music will be paused.Repressing it the music will be played again. DC IN MIC MIC ①Installation ear stabilizer hook ②Installation ear bud tip ear stabilizer hook you should NMotion Plus Bluetooth 4.0 Stereo Earbuds BTHL-251 BTHL-251 NMotion Plus Bluetooth 4.0 Stereo Earbuds Wireless technology using Bluetooth 4.0 A2DP Digital Volume Control Control unit has built in Volume, Play, Pause and Answer functionality Driver: 10mm Micro USB Port for battery charging Wireless Range: 33 feet DC Battery power: Built-in rechargeable lithium battery Battery life: Up to 6 hours of Talk/Music Time Stand-by Time: Up to 100 hours Includes: NMotion Plus earbuds 3 sizes of ear bud tips (S,M,L) 2 ear stabilizer hooks 2 sizing clips (to adjust cable length) 1 collar clip Carry pouch Micro USB charging cable