Add support to the Dura Slope® Channel Drain system to handle heavier traffic loads by installing the ductile iron Dura Slope Channel Drain Frame. The rugged frame sits on top of the channel drain and accommodates the standard iron or decorative iron drain grate on top. Provides NDS Class D load rating (up to 575 PSI) when installed properly; recommended for use with pneumatic tire traffic such as fork lifts and other heavy-duty hard tire equipment at speeds less than 20 mph; H-20 rated. The iron frame is painted black to inhibit rust and will form a protective iron-oxide patina over time