Arc'teryx Phase SL Bottom Men's 100% Polyester Imported 3" high 6" wide PHASE SL BOTTOM - Designed for high-output activities, the Phase SL bottom is a silkweight performance baselayer that rapidly wicks moisture, stretches with the body. ARC'TERYX ESSENTIALS - Versatile high performance designs for diverse activities and conditions. PHASE - Quick dry base layer with excellent moisture management. For high output activities. SUPER LIGHT - Superlight materials and design, emphasizing light weight and packability over durablity.