A maximum value option for entry-level UV protection. Short or long sleeve Basics U. P. F. 30 Sun Shirts are designed to keep you covered in the sun and surf and built to last in chlorinated pools. 30 U. P. F. Maximum Protection Strategic Seam Placement 2-way stretch Rash Protection Chlorine resistant Slim Fit Polyester Overlock Stitched: Super-Strong Seam.