Winter cardio of all kinds fuels our warm, breathable and uber-aerobic Fernos Vest. The key to its core-warming performance is 40-gram PeakFill™ Active Insulation, a highly breathable, quick recovery, spiral filament synthetic fill. Easily compressible into small spaces like a ski pack or running vest, it lofts back promptly when called on for treeline, ridgeline or rest-break warmth. Mechanical stretch and side-seamless construction enhance mobility and reduce layering friction. A single zip chest pocket secures a wallet and keys, while a rear drop tail and reverse coil YKK® zipper complete the fast, streamlined aesthetic.