Oenbopo Smart Bluetooth Music Wool Hat Wireless Handsfree Headphone Speaker Mic Knit Lint Cap Phone Calling and Answer for Iphone6 6s Samsung HTC LG Phones And iPad Pro Tablet (dark blue) Knitted material, fashion and keep warm with answer the phone in winter Size: Fits for head circumference 56-62cm Set-in MIC, available for cell phone to transmit the speaking phone to your audio devices directly so that the user can hand free answering Continuous working time:about 5Hrs Set-in Li-ion chargeable battery, charge via USB Cable, long stand-by time