Use in Concrete, Tile or Marble Size Color Coding Eight Different Sizes for Screws from #4 to #16 This popular design in CRL Expanding PVC Anchors give you tremendous performance in many building materials and are ideal for a secure installation of shower door hinges, clamps, and extrusions. Nine different size options give you just the right anchor for fastening versatility, and screw applications from #4 to #16. Their color coding makes picking the right size easy. Unaffected by moisture, so they resist corrosion and will maintain their firm grip.