Carson® TrussT valve boxes are value-engineered to achieve top-down strength for lasting access to irrigation systems. Sidewall feature "truss" reinforcements to withstand passing pressure from push-mowers, domestic riding mowers and other do-it-yourself gardening equipment. Boxes are made of structural foam High Density Polyethylene with UV inhibitors to provide a lifetime of consistent performance in a variety of weather conditions. This round box features a Twist-Lock Lid to resist mower suction, which helps preserve the lid and prevent costly damage to mower blades. Box has mouseholes & knockouts to accommodate many pipe configurations. The rolled collar helps ensure the cover fits properly every time. The reinforced bottom edge helps the box retain it shape after compaction. Light Duty: Pedestrian only. Can be modified in the field with a standard hole saw or jig saw. Made in the USA.