The post top shall be core cast aluminum. Aluminum shall be certified as pure #356 alloy, free of any porosity, foreign materials or cosmetic fillers. Castings shall be uniform wall thickness with no warping or mold shifting. Minimum wall thickness shall be 3/16". Electrical components are mounted in the ballast canister. The ballast canister shall be mounted in the post top with three stainless steel screws. A optional refractor will be a upgrade refractor globe or borosilicate glass refractor designed for either a type III or type V light distribution pattern.