About the productBluetooth version: 4.0 + EDR Bluetooth Profile: HFP 1.6, HSP 1.2, AVRCP 1.4, A2DP 1.2 NOISE REDUCTION: CVC6.0 INTELLIGENT Sound Mode: Stereo Operating Distance: 10 meters Charging time: about 2 hours Standby time: about 100 hours Talk/Playing time: 3.5 hours Power Source: Built-in Rechargeable Li-ion Battery Size: 40 x 24 x 32 mm / 1.58 x 0.95 x 1.26 inch Net Weight: 16.4 g HOW TO PAIR WITH: 1.Power on & Enter paring mode: Press the "power on" button for 5 seconds until the Blue LED light and Red LED light quickly flash alternatively (with "paring" voice) (Please don't stop pressing the button if you only see the Blue light flashing!!) 2.Use a bluetooth function mobile phone or other bluetooth master device. 3.Try to search the device and connect it(with "connected" voice). 4.Press the "power on" button once while the call is coming / end call. Latest Wireless Bluetooth 4.1 Technology with A2DP stereo music and AptX pure, clear sound, ideal for high quality music while running, jogging, cycling, skating, etcWhy opt for these earphones?PureSound In-ear white noise and listener fatigue reduction.Eliminates the white noise and delivers a clean audio experience offering hours of pure enjoyment You can easily stretch and move.Sweat-proof, durable design, Onscreen Battery Meter, Up to 5 hours of Talk/Playing Time and 145 hours Standby TimeHigh-fidelity stereo music and clear speech, You can begin enjoying CD quality stereo sound instantlyWhy choose us?We are dedicated to providing a wide range of high grade and one-of-a-kind products to our potential clients. For us, customer satisfaction is the topmost priority.