Bluedio Air Bluetooth 4.1 Headset Wireless Stereo Headphones,3D Surround,Mic know you are particular about headphones: you want them to be outstanding in performance, also to be stylish in look. But we're bold enough to take this challenge, and Bluedio A (Air) comes along. Our Bluedio A (Air) wireless headphones deliver your music with incredible depth and clarity, and get you noticed with stylish look. compatibility The Bluetooth perfectly works with your smartphone, tablet or Bluetooth enabled MP3 player. Note: there may be compatibility issue with other devices. Instruction tips: Turning 3D sound on: when the headphones are playing music via Bluetooth, press the MF Button and Vol+ Button together then release the buttons immediately. You will hear an indication note, the 3D sound is on.