Arc'teryx Atom

The Arc'teryx Atom Jacket is a go-to synthetic insulated layer for high-output days, delivering warmth without the bulk. Its Coreloft Compact 60 insulation stays warm even if hit by light moisture, and the air-permeable Tyono 20 shell works with stretch fleece side panels to dump heat when you're working hard. The result is a jacket that moves with you, breathes when you need it, and packs down easily for stowing in a pack.

This is the layer you reach for across a wide range of adventures—chilly forest hikes, exposed summits, climbing at the crag, and relaxed evenings at camp. It also slots neatly under a hard shell for backcountry touring and wet winter objectives, where its synthetic fill offers reliable warmth even when damp. Articulated patterning keeps mobility unrestricted, while an adjustable hem and No Slip Zip front closure help seal out drafts.

| Spec | Value | | Fit | Slim (fitted) | | Weight | 335g / 11.8 oz | | Insulation | Coreloft Compact 60 (60 g/m²) | | Shell fabric | Tyono 20, FC0 DWR | | Lining | 20D recycled nylon ripstop | | Side panels | Circular knit fleece (93% polyester, 7% elastane) | | Centre back length (size M) | 29" / 73cm | | DWR | FC0, free from intentionally added PFAS |