Our Heated WORKSKIN™ Midweight Base Layer is powered by our REDLITHIUM™ USB Battery Technology with carbon fiber heating elements to create and distribute heat to the chest and back. A one-touch LED controller allows you to select from two heat settings, delivering ideal heat for any environment. The Quick-Heat function allows you to feel heat 3X faster in the chest and upper back heating zones. Combining a double-lined polyester body and fleece-lined arms, the Heated MILWAUKEE® WORKSKIN Midweight Base Layer provides a versatile layering piece for total body warmth. This battery heated shirt features raglan sleeves and seamless shoulders for an improved range of motion and comfort while working. This heated base layer kit includes, (1) Heated WORKSKIN™ Midweight Base Layer, (2) REDLITHIUM™ USB 3.0Ah Battery (48-11-2131), (1) REDLITHIUM™ USB Battery Controller/Charger (50-59-2005), and (1) 3ft Micro-USB Cable and 2.1A Wall Charger (48-59-1202).