Tourmaster Synergy 2.0 Electric Dual Rheostat Controller - One Size Designed to operate in all weather conditions from a vehicle&rsquo;s 12-volt electrical system Warmth without bulk or discomfort, making for a safer, more enjoyable ride Lightweight, flexible steel fiber heating elements pro- vide safe, even warmth Expanding side panels help fine tune the fit and increase comfortAbailbale in size XS-4XL