AltoLoft Insulated Full Zip Jacket

**A lightweight down-alternative jacket with technical flair**

Our PROOF design knows that when it comes to perfecting an insulated jacket—it’s the inside that counts. The team opted for 40 grams of water-resistant PrimaLoft to help keep the jacket as breathable as possible without sacrificing warmth. (By the way, PrimaLoft was actually first developed for use by the US Army in the early 1980s, and the insulation worked so well that outdoor brands poached the technology for themselves.) The shell of the jacket is treated with a durable water repellent (DWR), and blended with a touch of spandex to help keep its shape and allow gentle flex. Combine all these technical elements with the fact you’ve got a pack-friendly design (it can roll up for storage in a daypack), streamlined zip pockets, and a soft quilted liner, and you’ve got a damn good full zip primed for impromptu, one-bag-travel trips.