A lot of shells promise year-round versatility, but there’s always a tradeoff: either too streamlined for winter or too hot and heavy for summer. This one’s just right. The lightweight, three-layer armor proved its mettle on February ski tours, when the brimmed hood shielded our eyes from windblown graupel and the tough fabric shouldered skis without ripping or scuffing. Yet it didn’t stifle on June hikes along Colorado’s Continental Divide Trail. “Through 7 months of testing and a huge range of weather conditions, this jacket has managed to be exactly what I needed in every situation,” says our Colorado-based editor. Its secret is the fabric: a 40-denier nylon with “false twist” yarns that are crimped, making them particularly stretchy and abrasion-resistant. Result: The material is uncommonly tough for the weight, but still thin enough to enhance breathability. It’s also soft for a hardshell, thanks to Gore’s new C-Knit membrane, which is constructed of supple knit loops instead of the traditional rigid weave. Result? The Zeta feels gauzy over a short-sleeve T-shirt during summertime rainstorms, rather than clammy and heavy, like many winter shells. The fabric prevents wind from penetrating, but because it’s not a stiff shield like heavier fabrics, we could feel the effects of big gusts. Features are efficient and functional: One cordlock behind the head cinches the hood; Velcro tabs seal the cuffs; zippered pockets (there are three) hold an iPhone 6 and inclinometer; a hem cord seals out wind. Packed, it’s softball size—so we take it everywhere.