The Arcteryx Atom Hoody is a lightweight insulation piece for the active user providing insulation while ensuring mobility with a good level of breathability. Depending on the conditions, this versatile jacket can be used as either a super warm mid layer or an outer layer and for a range of activities. The jacket uses Coreloft Compact 60 insulation, a lightweight synthetic insulation that is very compressible and light but expands very quickly when unpacked. Coreloft Compact 60 retains its ability to loft much better after repeated compression, extending the overall lifespan of the jacket. The outer is a lightweight and soft Tyono 20 fabric that has good air permeability and a DWR treatment on the face providing water repellency and wind resistance. The side panels in the body are Performance stretch fleece which provide this jacket with exceptional breathability and mobility, but if it gets really cold or you slow down it will be these areas where you will feel the cold first. The No Slip Zip is an Arcteryx feature which works like a series of speed bumps down the zip so the zip doesn't slip from the position you put it in, even when its not fully zipped up. The insulated StormHood hood on the Atom LT Hoody has been designed to give you full weather protection. It can be adjusted single handed and will stay in place, not obscuring your view as you rotate your head. It is not designed to fit over a climbing helmet as it's low volume, but it will sit quite nicely under one. Arcteryx Atom Hoody Features Coreloft Compact 60 synthetic insulation Performance stretch fleece side panels Tyono 20 outer with DWR finish Adjustable and insulated StormHood No Slip Zip main zip 2 zipped hand warmer pockets 1 zipped internal security pocket Adjustable hem Stretch knit wrist gaskets Fit:Trim and hip length. Weight:370g Arcteryx Atom Hoody