Wear our electrically heated jacket liner over a t-shirt and under an outer jacket to maximize heat retention. Connects directly to the 12V battery in your motorcycle, snowmobile, or ATV for non-stop heat. Add a portable battery pack to keep the heat going even when you're not riding. Features: Leverages ZEPTO fibre technology; made in France, these heating fibres are so thin you wouldn't be able to notice them if not for their tremendous heat output Flexible lycra panels along the side allow full range of motion and breathability Windproof and water-resistant fabric Uniform heat delivered all over the front, back, and collar Premium heating wire is made in the USA Women's version has two side pockets and a more slim tapered fit Men's version has a zippered chest pocket Ribbed cuffs for maximum comfort and heat retention Pairs seamlessly with our heated gloves or glove liners via the convenient hideaway plugs at the end of each sleeve Portable Battery Add-on - Consider purchasing one of our Heated Clothing Portable Battery Kits if you'd like to use your heated jacket when you get off your vehicle. In other words, a portable battery will allow you to use this jacket while skiing, snowboarding, or just taking a walk on a cold day. Sizing: When worn, the heated jacket should be touching the body profile as much as possible, leaving no room for extra movement. Choosing the correct size mostly depends on your chest measurement. For example, a medium-size jacket is a good choice for a person with 42 inches around the chest. Wear a t-shirt while taking your measurements for the most accurate results. Wiring: One 20" long Coax Battery Cord (SKU 100227-1) is included - You will require ONE of the below switch cords OR temperature controllers Male Coax to Female Coax Switch Cord (SKU 100222-1) Dual coax switch cord (SKU 100225-1) Required only if you plan to use the heated gloves or glove liners in conjunction with this heated vest Allows you to turn this vest and your g