Gerbing's Core Heat Core Battery Heated Softshell Vest Includes a 7V 2.2Ah rechargeable lithium battery that hides away in a zippered pocket. Enjoy a whole day of soothing warmth with a single charge. Heating Elements Perfectly Placed by Chest and Back Lightweight, ultra-breathable soft shell with a laminated fleece lining ideal for layering or wearing alone Wind-resistant & Water-resistant Chest Size: 40/SM, 42/MED, 46/LG, 50/XL, 54/XXL