Description of Marmot Lightweight Crew SS For warm weather when base-layer breathability is essential, the Lightweight Crew SS delivers maximum performance, while its design gives it the appeal of an outer layer. Features: Main Material: Polartec® Power Dry® with Cocona® performance technology Fabric Stretch Ensures Perfect Fit Flat Lock Construction Natural Anti-odor Management Polartec® Power Dry® with Cocona® Performance Technology Polartec Power Dry with Cocona Performance Technology Quick Drying Tag-Free Neckline Eliminates the Desire to Reach Back and Rip Out An Itchy Tag Wicking Moisture Management