Size 3XL. Powerlet's Premium Heated Liner is manufactured with ProForm panels, a premium collar, unique sleeves, full heat coverage, and zippered cable openings. ProForm panels stretch for maximum heat transfer, simple sizing and freedom of movement. Stay Warm While Riding: Powerlet's 100 watt ProForm(tm) heated jacket liners pack down to a very small size to fit on the bike when not in use. Not only the warmest heated clothing available, but our ProForm stretch panels also make them the most comfortable. We recommend using a temperature controller with the ProForm 100 watt jacket liners. The ProForm Advantage: ProForm(tm) stretch panels provide three key advantages: non-binding movement, maximum heat transfer and simple sizing. While all three are very important, maximum heat transfer is perhaps the most important. For maximum heat transfer the heated garments must be close to the body. A long sleeve T-Shirt is recommended under the garment. A heavier layer can be worn over the garment. Other heated clothing manufacturers provided many sizes to attempt to create a snug fit. This often leads to a more complicated purchase and the potential improper fit if your weight changes. ProForm 100 Watt Jacket Liner Features: ProForm stretch panels provide comfort and simple standard sizing. Ultra thin design provides comfort and small storage. Comfortable heated Polartec fleece collar wicks moisture. Glove connectors are located at the ends of the sleeves. Unique sleeve finishing reduces bulk around wrists. Zippered pockets manage power cables. Handy stuff sack allows for storage on the vehicle. Ordering Heated Clothing: Three parts are required for heated clothing: the power outlet on the vehicle, the temperature controller and the heated garment. Simply put, the temperature controller and cables connect the garment to the power outlet.