This quarter-zip fleece (OL) is warm, packable and weighs next to nothing. And because itís produced from recycled PET bottles, itís also good for the environment. You can wear this robust pullover as a mid-layer in a technical layering system or slip it on over your baselayer for a little extra warmth during rest breaks on the trail. When it comes to versatility, this quarter-zip fleece is pretty hard to beat.