The NDS Standard Series 14 in. x 19 in. valve boxes and covers are injection molded of structural foam polyolefin material with a melt index between 10 - 12. Coloring and UV stabilizers are added, along with processing lubricants when needed. The 14 in. x 19 in. body shall be tapered and have a minimum wall thickness of 0.200 in. The body shall have a double wall at the top cover seat area with a minimum thickness of 0.250 in. The cover seat area shall have 16 structural support ribs on the underside of the seat, each with a minimum thickness of 0.250 in. The bottom of the body shall have a 0.500 in. flange. The 12 in. x 20 in. cover shall have an average thickness of 0.250 in. Color: Sand/Matte.