From Ryno
Ryno Flat Flange Rainwater Outlet Leaf Guard prevents the ingress of leaves and other debris into the rainwater outlet. For use with Flat Flange Rainwater Outlets: Benefits Manufactured to the highest specification Incorporate a clamping ring that creates a secure, leakproof seal between the roofing membrane and rainwater outlet Remains flexible, even at very low temperatures Suitable for all atmospheric conditions