Tenergy Twisted Cable Knit Wireless Hands-Free Bluetooth Beanie Hat 52424 - Tan Bluetooth Version V 4.1 +EDR. Compatible with all Bluetooth devices Built in rechargeable Li-Ion battery provides up to 6 hours of playtime. (USB charging cable included) Wireless range up to 33 feet Built-in microphone allowing you to talk hands free Washable beanie after removing headphones