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 a streamlined minimalist set of features to provide very light weight. These CoreloftTM insulated pants are designed to keep you warm on the coldest days, or to be used as an extra outer layer during low activity moments in the mountains. Features: Breathable Insulated Lightweight Compressible and packable Wind resistant DWR finish Durable Water Repellent helps repel water from fabric surface Articulated knees and seat Laminated wind flap Bottom snap closure on zip Full length separating side zippers to allow removal over boots and crampons Adjustable pant cuff drawcord Elasticized waist Internal stow pocket with attachment point Trim Fit Weight: 335 g 11.8 oz Activity: All Round Materials: 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.