The Arc'Teryx Theta AR Jacket is the perfect all around jacket for any outdoor activity and the most popular shell Arc'Teryx makes. Like all Arc'Teryx hard shells, the Theta AR Jacket has welded, not stitched seams. This makes it stronger and cuts down on weight. It's also got watertight zippers. They’re so bomber, they preclude the need for a stormflap, again cutting down on weight. Arc’Teryx was the first company Gore-Tex allowed to do this and still use the Gore-Tex name. Seam allowances are also super tight and thin. Toss in molded zipper garages and low volume helmet capacity and you've got yourself a indomitable jacket.