Protect the Dura Slope® channel drain system from harmful leaves and debris by installing the slotted grate on the EZ-Track™ Radius Coupling. This heavy-duty ductile iron grate has an open surface area of 1.88 sq. in. per grate and 5.75 GPM flow rate. Rated for NDS Class D loads (up to 575 PSI) when properly installed. Iron grates are painted black to inhibit rust and form a protective iron-oxide patina over time.