Keep the Dura Slope® channel drain system with slot tops clear of obstruction by installing with the Maintenance Unit. The removable stainless steel box can be lifted to provide access inside the channel to remove blockages that can impair drain performance. Maintenance Units can be filled with bricks, concrete, or asphalt during installation to blend into the surroundings. They should be installed at the beginning and end of the drain run and at intervals of approximately 100 ft