FNDN Heated 3.7V Sports Socks Whether you’re slipping them on underneath boots, shoes or ice skates, the FNDN Rechargeable Heated Socks can keep your feet warm and comfortable all day long. Forget about frozen toes or discomforting pain in the winter mornings or evenings. We’ve found the solution by designing a sleek and trendy rechargeable sock for women and men. The heated sports socks offer enough warmth to provide great relief from poor circulation, arthritis, Raynaud’s Syndrome and any kind of winter cold issues. The FNDN Heated 3.7V Sports Socks are powered by our proprietary Radiant Core Heat technology and USB rechargeable BEGO battery system. This battery is the smallest & lightest in class, designed to provide the most power with the smallest footprint possible. Features: Machine Washable (*Must Remove Batteries), Lay flat to dry Small & Lightweight high-performance BEGO Battery System Universal USB Charging FNDN Heated Sports Socks Include: 1 Pair Sports Socks 2 3.7V Li-Ion Rechargeable “BEGO” Batteries 1 USB Dual Battery Charging Cable Fabric: 65% Merino Wool, 5% Spandex, 30% Nylon Size Information: S/M: Men's 4-9.5 and Ladies 6-11 L/XL: Men's 10-14 Care Instructions: Machine Wash Delicate (Remove Batteries) Do Not Use Bleach Do Not Machine Dry Do Not Iron Read more (2) BEGO Batteries Included comes with USB Charger Up to 4.5 Hours of Battery Life High-Rise Wool Fabric Read more Read more