Sony MDR-AS600BT Active Sports Bluetooth Wireless In-Ear Headphones - Black (Certified Refurbished) Enjoy high quality Bluetooth audio streaming and simplified connectivity with Near Field Communications (NFC) technology. Simply align your compatible devices to activate or deactivate pairing.Splash-proof design. The sleek, splash-resistant housing prevents sweat and water from leaking in, making these headphones ideal for an active lifestyle.One button control. Pressing the multi-function button in various, deliberate ways allows you to Play/Pause, select the Next/Previous music track, make or receive a call, or even adjust the volume.Hands-free calling. A built-in microphone makes hands-free phone calls a breeze. Once your phone is paired, simply press the phone button on the earpiece to accept incoming calls, and press it again to end the conversation.Up to 8.5 hours battery life.