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. Grates fit directly into sewer & drain fittings, corrugated and S/D pipe without use of a coupling. Not for use in areas subject to vehicular traffic. Fits 9 x 9 catch basin No.TTCB2090920/4090921 and 9 x 9 low profile No.TTALP090924. 27.29 sq.in. open surface area. 5/16 in grate opening. 61-175 PSI. ADA compliant.