Corefyco Bluetooth Headset, Wireless Earpiece Hands Free Stereo Headphones Business Earphones in-Ear Earbuds BUILT TO STAY COMFORTABLE BUILT TO STAY COMFORTABLE NEVER POWER OFF HANDS-FREE CALL & BUILT-IN MIC: 33 feet, with a high-quality built-in microphone for hands-free calls. FOLDABLE DESIGN WITH A HARD CARRY CASE : The foldable Headband makes it easy to carry and store away. Bluetooth Solution: CSR8635 Bluetooth Version: 4.0 Support Agreement: A2DP, AVRCP, HFP, HSP Operating Distance: 10 Meter Battery: 540mA Charging Time: About 2 Hours Play time: 25 hours Driver Unit: 40mm Impedance: 32 ohms