Atom Series: Insulated mid layers made with hydrophobic synthetic material that resists absorbing moisture. Outer fabric has a water repellent finish. LT: Light Weight. Built with highly durable top performance materials but designed with streamlined minimalist set of features to provide very light weight. CUSTOMER SERVICE TIPS Arc teryx Atom LT products have non locking zippers by design. One purpose of the non locking zipper is that it is easier to operate with one hand. This design feature also helps to limit the possibility of damage to the zipper and lightweight face fabric directly adjacent to the zipper. This sleeveless core heater hugs the body with efficient CoreloftTM insulation to preserve warmth while durable fleece side panels made with PolartecR Power StretchR with HardfaceR Technology increase active use breathability and mobility. A wind and moisture resistant outer shell extends stand alone usability. Features: Moisture resistant outer face fabric Breathable Insulated Lightweight Compressible and packable Wind resistant DWR finish Durable Water Repellent helps repel water from fabric surface Composite construction Breathable, stretch side panels for enhanced comfort and mobility Soft, smooth lined collar Full front zip with wind flap Stretch knit cuffs Laminated hem Drop back hem Internal chest pocket Two hand pockets Trim Fit Weight: 220 g 7.8 oz Activity: SkiSnowboard Ice Climbing Alpine Climbing Hiking Trekking Materials: PolartecR Power StretchR with HardfaceR Technology 88% polyester, 12% elastane, 230 gm . A four way stretch fabric that allows for excellent athletic movement and good breathability to maintain comfort. Some products feature HardfaceR Technology for a higher level of abrasion resistance. CoreloftTM 60 60 gm insulation. Made with highly crimped multi denier siliconized polyester yarn, this lightweight, breathable, and thermally efficient, 100% polyester staple fibre is very compressible and has excellent loft retention. TinthanTM 100% nylon 1.9 ozyd , 46gm . 20D mechanical stretch nylon rip stop with an air permeable polyurethane coating DWR finish. This lightweight stretch fabric has good abrasion resistance for its weight.