The Volt 7v Insulated Heating Vest was developed to be ultra-lightweight but with stellar heat retention capabilities. Constructed with an extra soft, 20 denier min-ripstop nylon lining and quilted shell and lined with 80 grams of lightweight, compressible and high retention insulation, not only will the vest heat up on command, it will hold the heat better than any vest on the market. This powerful heated vest features a 4 panel, 3 zone heat system concentrated in the chest and back that is powered by a 7v lithium battery. No matter if you are climbing the nearest mountain or going down the block to get groceries, this vest?s form, fit and function is second to none. Includes lycra thumb through cuffs to help keep a firm fit and to seal out the cold. 90 Day Manufacturer Warranty Color: Black 4 Panel Heating System Safe & Durable Heating Technology 80 grams of lightweight, thermally efficient polyester fiber insulation Silky soft mini rip-stop nylon shell and lining 3 zone heating with 2 panels in the chest and a large back panel Provides up to 170 degrees of soothing heat for 2 hours on the highest setting Includes 7.4v 2900mAh battery and charger Zero Layer heat system eliminates bulk and more efficient heat transfer Volt Resistance CRACOW Insulated Heated Vest Includes 1 – Heated Vest 1 – 7.4v 2900mAh battery 1 – Battery Charger Instructions Warranty Volt Heated Vest Size Guide: Small: 36-37 chest Medium: 38-39 chest Large: 40-42 chest X-Large: 43-44 chest XX-Large: 45-48 chest Approximate Battery Run Time per Power Level: 100% High ? 2.5 hours 75% Med/High ? 3.5 hours 50% Medium ? 5 hours 25% Low ? 10 hours Volt Resistance Zero Layer Heating Technology Our patented Zero Layer heat system helps eliminate bulk while providing more efficient heat transfer than any other heating system available.What do we mean by more efficient? To keep it simple, it is because we basically eliminate the need to ?hide? our heating system behind additional fabric layers which impedes heat transfer. This translates to more heat, better heat coverage, less battery power and longer run times.Each of our ultra-thin heating panels are constructed using tiny, imperceptible stainless fibers that are woven onto an insulated fabric. We then encapsulate these heating elements with a special thermal bonding sealing tape ? permanently protecting the heating panels and connections from the wear and tear caused by the rigors of daily use making it not only durable but also waterproof.Each heating panel is engineered to provide a specific amount of instant heat that evenly radiates warmth to the body to help chase away the cold.