Grate Square Black 12In Made of highest quality structural foam polyethylene with UV inhibitor. May be used in turf or concrete applications such as lawn areas, walkways, patios and pool areas where effective surface water removal systems are required. Not for use in areas subje ct to vehicular traffic. Fits 12 x 12 catch basin series and 12 x 12 low profile adapters. 51.79 sq.in. open surface area. 5/16" grate opening. 61-175 PSI. ADA compliant.