The Castelli Fly Vest is a paragon of modern design that prioritizes both function and the environment. Constructed with super-lightweight materials, it offers just the right balance of warmth and protection without any unnecessary weight. The low/no collar design aids in optimal temperature regulation, ensuring you remain comfortable in various conditions. With the cutting-edge Castelli FLY Fabric Technologies (FFT) at its core, the vest is backed by GORE-TEX INFINIUM™ WINDSTOPPER® inner lining and the revolutionary CLIMA SL Insulation for superior warmth. The FLY SL Shell provides stalwart defense against wind and rain. Not only is it functionally supreme, but it's also environmentally conscious with a 100% recycled post-consumer outer shell and lining. Practicality is emphasized with a top and bottom-opening YKK® Vislon® zipper, three back pockets, and an additional zippered security pocket for your valuables. To ensure a snug fit, the waist is equipped with elastic and silicone. Plus, for those night-time ventures, there's added reflectivity at the waist. Elevate your outdoor experience with the Castelli Fly Vest.