MAXROCK Bluetooth Headphones, Wireless Bluetooth 4.0 Sports Headphones with Microphone (Black&Yellow) Up to 4 hours of Talking/Playing Time, standby up to 250 hours High-fidelity stereo music and clear speech Easy-of-using: control volume, select songs and receive phone calls via the buttons on the interfaces. Universal device compatibility: compatible with most Bluetooth-enabled devices, such as iphone, ipad, Laptop, and so on. 10-meters of working distance, Bluetooth 4.0, suitable for indoor exercises freely