A piece of high-tech magic from Patagonia. Seriously, the Micro Puff Jacket weighs about the same as a banana, yet it delivers alpine-grade warmth and the versatility of synthetic insulation. Patagonia calls it "the best warmth for weight jacket we’ve ever built," and this is no small thing. PlumaFill insulation is a featherlight alternative to down: light, compressible and it retains warmth when wet. It's housed in a 10-denier nylon shell that's DWR-treated to repel rain and snow. The design is intentionally spare, with elastic at cuffs and hem and drop-in inner pockets that share the pocket bags of the handwarmer pockets. It's all sewn together with a unique quilting pattern that holds the fill in place without an excess stitch.