PLYMOUTH SUPERFLEXION® Material · Stronger than Structural Foam, Greater Top-Load Strength · More UV and Wear Resistant than Structural Foam · 10 Year Lid Guarantee Lighter than Cast Iron or Concrete Boxes · Easier Warehouse Handling · Lower Injuring Potential Snap Locks on Drop-in Lid · Discourages Vandalism · Keeps Lid Intact in High Water Lids Are Easily Interchangeable · T-Top Lid Will Fit Boxes of Other Manufacturers Lids Come in Green, Boxes Are Available in Black (6", 12" High)