Helly Hansen H2Flow Jacket

www.hellyhansen.com, 15.6 ounces
This unique variation on the venerable shelled fleece jacket design truly impressed us during recent tests, with its excellent insulation-to-weight ratio, easy venting, and fast moisture transfer in sweaty situations. At first glance the H2Flow looks like a standard hoodless zip-front jacket with a taffeta outer shell, fleece inner, and twin zip pockets. However, the shell fabric isn’t nylon, it’s tougher polyester, which resists UV degradation and doesn’t stretch or absorb water when wet. Beneath that is a 200g Polartec brushed fleece with yet another difference,  a Swiss cheese pattern of circular cut-outs that trap air to increase insulation, while also helping to disperse sweat vapor. The cut-outs are body-mapped, with larger holes and closer spacing in high-sweat areas like the central back, while smaller, widely spaced holes cover the chest and midriff.

The side panels and sleeves are lined only with a lightweight brushed nylon, while the fleece torso is further lined with a loose open mesh for slippery layering and free air flow. As if that weren’t enough, two foot-long zippered vents run down the chest, and the pockets are all mesh, forming de facto vents as well.

The overall effect is a jacket that’s nearly as warm as a puffy when zipped up, but resists rain showers, transfers sweat better, and vents far more than either puffies or standard shelled fleece. The weather resistance and wide temperature range made it perfect for humid, chilly camp evenings and soggy autumn trail runs on damp, cold, 11,000-foot Boulder Mountain. It’s already become one of our key layering staples, as fall progresses into winter.
- Steve Howe