Comfortable, durable and well crafted, this M12 Heated Ripstop Black Vest, Small (Vest Only) (2172-S) from Milwaukee is an impressively versatile piece of work wear. It boasts rugged wind and water resistant construction, and features high loft insulation along with thermal lining. Capable of keeping you warm in cold weather, it's excellent for use as a three-season layering piece. Plus, carbon fiber heating elements provide adjustable heat to core body areas. The heating elements can run up to six hours on an M12 REDLITHIUM compact battery.