Block pipe-clogging leaves and debris from entering the drainage system with the trench drain grate. This ductile iron grate features a bar design and is rated for NDS Class E loads when properly installed. The ductile iron drain cover has an open surface area of 227.0 sq. in. per meter and flow rate of 695.6 GPM per meter. Two half-meter (19.69 in.) grates will cover one BG-FILCOTEN 300 12 in. trench drain. Iron grates are painted black to inhibit rust. Over time, it will form a protective iron-oxide patina.