The synthetic layering piece for the woman who prefers to leave a hood off of her midlayers, the Arc'teryx Atom Women's Jacket has a trim fit for gliding into that next layer, stretch side panels for extra venting and movement, and a light packability that makes this a must have core wardrobe essential. The light, soft to the hand, Tyono™ 100% nylon 20 denier shell is treated with DWR for water repellency and supported by Resilient Coreloft™ 60 synthetic insulation, a product that is warm, light, and designed to move moisture from your core through to the air permeable outer face fabric so it evaporates quickly, helping you maintain an optimal environment under your midlayer. Nicely articulated for movement with gusseted underarms for mobility this has a No Slip-Zip that allows you to set the zipper where you need to for optimal venting0 and it won’t shift or work its way down while you’re in motion. For the woman who prefers the easy care of a synthetic insulation that won’t lose loft when damp this is your midlayer.