concentration & meditation mode use the wireless charging speaker in your room, office or study, you can switch thems according to the different moods,itis a good partner to adjust the atmosphere ,it will help you calm down and enjoy your yoga,spa and relaxation time. .wireless charging power 15 w bluetooth vertion ; 5.2 bluetooth name ; bt2301 bluetooth frequency ; 2.4 GHZ- 2.48GHZ Transmission distance ; 10 m frequency response range ; 50HZ-20KHZ signal to noise ratio of the whole machine ;>75db built-in lithium battery voltage ;3.7v charging input :DC5V/500MA