Opteka BTX-5 Over-The-Ear Wireless Bluetooth 4.0 Stereo Headphones with Built-in Microphone, 15 Hour Battery and Hard Travel Case Bluetooth stereo headphones with advanced Bluetooth CSR version 4.0 latest technology with a range 32.8' (10 m). No more wires, stream music directly from your smartphone or tablet, and be free of annoying, tangled cords. Charges quickly and lasts hours, the lithium-ion battery gives you up to 15 hours of battery life. Integrated controls easily make and receive calls, choose next and previous tracks, and raise or lower the volume while on the go. Pressure-relieving cushions sit gently on your ears for a comfortable acoustic seal and powerful bass response.