Upf 40+ Sun Protection Some 686 Garments Come In Either 2-Way And 4-Way Stretch Allowing For Ultimate Freedom Of Movement. Moisture Wicking Fabric That Lets Your Body Regulate Its Temperate By Moving Sweat To The Outer Surface And Drying Quickly. Upf 40 A Upf 40 Rating On A Garment Indicates The Fabric Will Allow 1/40Th (Roughly 2.5%) Of Available Uv Radiation To Pass Through.