Gravel-Excluder-Leaf-Excluders prevent dirt and objects from entering the drains, ensuring optimal rainwater runoff and containing the gravel in the waterproof membranes. Gravel-Excluder-Leaf-Excluders are used to stop dirt and various objects from entering the drain, obstructing the regular runoff of rainwater; to ensure maximum effectiveness, it is recommended that the drain opening be periodically cleaned of any dirt that may be present.