Heated Core Heat Men's Softshell Vest (Battery Powered, Medium) Includes a 7V 2.2Ah rechargeable lithium battery that hides away in a zippered pocket. Enjoy a 2 to 10 hours of soothing warmth with a single charge. Use the built-in controller to regulate your desired heat output Lightweight, ultra-breathable soft shell with a laminated fleece lining ideal for layering or wearing alone Brushed collar lining and fleece-lined pockets Reverse-coil zippers and hem-cinch pull cord