The Alfar has a pretty cool hybrid construction consisting of Polartec Powerstretch Pro in the sleeves, under arm & hood panels. Where as the main body & hood are made up from Neutron 120 synthetic insulation encased in a 30 denier, micro rip-stop nylon, windproof fabric with a DWR (Durable Water repellency) finish. Super techy with a close, fully articulated athletic fit, useful thumb loops & harness compatible hand pockets. The Polartec Powerstretch Pro panels allow for reduced bulk when layering & increased breathability in warmer areas such as the underarms. The Neutron synthetic insulation traps the warm air between its fibres and the windproof outer fabric prevents that warm air from escaping. So the different parts of this jacket work together to regulated your body temperature & maintain a great level of comfort. Use the Alfar as a lightweight active outer piece in fair conditions, or in colder climates you can use is as part of a modular layering system as a good weight mid-layer. Polartec Powerstretch Pro sleeves NEUTRON 120 main body synthetic, breathable insulation 30 Denier windproof, micro rip-stop nylon main body outer with DWR finish Athletic, streamlined, articulated cut Flatlocked anti-chafe seams Harness compatible pockets with YKK zippers & front facing insulation Roll-away thumb loops & back-of-hand protection Paneled hood with NEUTRON 120 synthetic, breathable insulation in centre; stretch Polartec Powerstretch Pro at sides YKK centre front zipper Corded, glove compatible zipper pulls One-handed, elastic hem drawcord operation Embroidered logo front & rear