D1 140mm H 160mm Helps to ensure that water can drain efficiently. They can fit into all designs of circular outlets and connectors. They are compatible with all the different materials manufactured. They are designed with 12 rods at the bottom which have a slightly serrated edge, so that the leaf guard can be inserted into the hole and the edges will grip onto the inside of the drain connector or outlet, which has a series of small ridges around the inside rim of the shaft.