Arc'teryx Proton SL Hoody

The Proton SL Hoody is the lightest, most breathable piece in Arc'teryx's insulation collection, engineered for high-output pursuits in cool conditions. Its knit insulation holds loft and shape through repeated pack stuffing, while the Fortius™ Air 20 face fabric balances air permeability with weather resistance, stretch, and lightweight durability. An FC0 DWR finish repels moisture without added PFAS, and the octa-loft lining helps regulate temperature during intense climbs.

This hoody performs best when you need to move fast and stay warm without overheating. Whether you're on an alpine route, a cold-weather rock climb, or any other demanding activity, the articulated patterning and helmet-compatible adjustable hood provide freedom of movement and protection. The result is a versatile, packable layer that breathes when you're working hard and insulates when you pause.