Proton SL Hoody

The Proton SL Hoody is the lightest, most breathable piece in Arc’teryx’s insulation line, a men’s layer for cold climbs and high-output days in cool weather. The insulation is Octa Loft, a 98 g/m² polyester knit that lets the body breathe through a hard push and holds its loft and shape however often it’s stuffed into the bottom of a pack.

Outside, Arc’teryx balanced airflow against weather. The face is Fortius Air 20, a 58 g/m² weave of 88% nylon and 12% elastane with a water-repellent finish free of intentionally added PFAS. The insulated hood adjusts and fits over a helmet. The fit is trim and articulated to move with the body, and it weighs 370 g. Shown in Black.