... -in lithium battery -volume control buttons - Bluetooth v2.1 Flower design Bluetooth wireless headset for iphone A, play, pause functions;B ... battery, 25 minutes fast charging;E, double track stereo, calls can be free to talk;F, volume ... highest wireless solutions, avoid interference with other Bluetooth signals. Specification: Bluetooth version: Bluetooth specification v2.1, compatiblev1.1, v1.2 ...