The Montane Sirocco Lite's wind resistant, 100% recycled FEATHERLITE AIR covers the core is coated with a PFC-free DWR to handle passing showers. Then, Montane's own insulation, designed for 4-way stretch, keeps you warm without overheating. Finally, the hybrid construction uses THERMO STRETCH LITE fleece on the arms, allowing this hybrid garment to move with you and enable high performance in the mountains, whether you're climbing a pitch or hiking down the trail.