New four-level push button 7.4v design. Wind-Shark soft shell breathable and treated waterproof fabric construction. Microfiber-lined collar and interior of vest. ESO locking front zipper, front hand pockets, inside storage pocket. Shock cord waist adjustment. Lycra cuffs for comfortable and secure fit. Three 6.5" x 2.5" heating panels lined with steel alloy fiber elements. Optimum placement of heating panels, with two on the chest and one on the back. Battery life ranges from 2.5 hours on high to 10 hours on low temperature setting. Surface temperature ranges of 135 degree/100%, 120 degree/75%, 105 degree/50%, 90 degree/25%. Includes one 7.4v 2.0Ah rechargeable lithium-ion battery and dual charger (packaged separately).