For over 15 years, the Sigma Jacket has represented what is possible with down insulation products: a leading light in modern alpinism. Lightweight, packable and highly water-resistant, it’s a premium performance down jacket that keeps you warm and protected during serious alpinism and mountaineering efforts where only the essentials make the cut. On multi-day expeditions among the giants of the world’s high mountains or technical lines in lone alpine cirques, it provides the warmth you need without the weight and bulk you don’t.

800-fill power goose down is strategically distributed through the jacket and held in place by the stitched-through baffle construction, optimising warmth and preventing down migration that can lead to cold spots, particularly in vulnerable areas such as the shoulders, chest and hood. Our down is minimally treated and DOWN CODEX approved, meaning it’s sourced through a transparent and carefully audited supply chain.

Lightweight and highly water resistant Drilite Loft outer fabric allows the down to loft to its full potential, providing maximum warmth while protecting it against melting snow, ice and howling spindrift. Drilite Loft also offers complete wind resistance and excellent breathability, keeping you warm and comfortable even when working hard. This protective outer fabric also extends around the inner hem and the hood lining, protecting you and the jacket inner from moisture ingress in these typically vulnerable areas. Meanwhile, seam-free shoulder panels improve water resistance even when wearing a pack.

The Active Alpine Fit accommodates the dynamic needs of alpinists, eliminating excess material and bulk that can encumber activity or obscure access to a harness while still allowing for complete freedom of movement, whether shouldering a pack, swinging axes or coiling ropes.

The grown-on insulated hood uses our patent-pending Firestorm construction, combining a sewn-through baffle structure with a drop outer fabric to provide an invaluable defence against the elements in severe conditions. Baffle pleats reduce the overall volume without compromising warmth, and a pleated halo baffle around the face offers reassuring warmth and protection against freezing winds and spindrift.

Internally, two large drop pockets make it easy to store gloves, hats or other essentials that need to be accessed easily while on the move.