Rab Cirrus Flex Jacket is an ideal layer for getting active in the outdoors. It's made using very breathable Hyperlite ripstop fabric outer & lining fabric, filled with Cirrus featherless insulation & has Thermic stretch fleece panelling at the sides that gives you extra mobility while keeping you covered. Its 'slim' cut means that it will fit nicely underneath a waterproof shell. It has large, useful pockets inside & out, & the left hand pocket doubles as an integrated stuff sack making it very easy to take with you wherever you go. Hyperlite ripstop outer & lining fabric Cirrus (powered by 3M) featherless insulation Thermic stretch fleece panelling YKK Vislon front zip with internal storm flap 2x YKK zipped hand pockets (Left doubles as stuff sack) 2x interior drop-in pockets Lycra elasticated cuffs, hem drawcord Cirrus (powered by 3M Featherless technology) uses technical, water resistant fibres in a “down-like” structure to deliver the same warmth for its weight as 600 Fill Power duck down. It lofts freely, compresses well when packed & is robust & durable. Its moisture resistance, warmth when wet & speed of drying are very high: superior even to Rab's Hydrophobic Down.