NDS Valve Boxes are designed to offer years of service under the most demanding outdoor conditions. This NDS Valve Box has a 8" x 12" body that is tapered and has a minimum wall thickness of 0.187". The body has a double wall at the top cover seat area with a minimum thickness of 0.200". The cover seat area has 10 structural support ribs on the underside of the seat, each with a minimum thickness of 0.150". The bottom of the body has a 0.375" flange. The 8" x 12" cover shall have an average thickness of 0.150".