The stylish Kiaro slot design drain grate elevates the look of your drainage system. Linear openings allow water to pass through while solid bars block leaves and debris from entering and potentially blocking drain pipes. The drain cover has an open surface area of 66.0 sq. in. per meter and 202 GPM flow rate. Rated for NDS Class D loads when properly installed. Grate is ADA compliant and heel proof. Two half-meter (19.69 in.) grates will cover one BG-FILCOTEN 100 4 in. trench drain. Iron grates are painted black to inhibit rust; over time, it will form a protective iron-oxide patina.