The Cirrus Flex Jacket is a light synthetic jacket, insulated with 3M Featherless insulation in a windproof Hyperlite ripstop shell. Underarm and side panels utilise Thermic stretch fleece for better breathability and movement. The trim style and smooth shell means it layers nicely under a shell, but it's perfect on its own in slightly nicer weather. Cirrus Flex Jacket - Men's