Raises Drain Screens by 1/4 inch. If the drain requires more than 1/4 inch Additional Kits can be used together to extend drains by more than 1/4! Description Give your tile floor a finished look by raising low drain screens with the Extend-O-Drain® Floor Drain Height Extension Kit! Available Kit Sizes 2-1/2" to 3" Diameter Kit 3-3/8" Diameter Kit 4-3/8" Diameter Kit Note: Measuring the entire drain screen diameter will result in the incorrect kit size. The correct kit size corresponds to the distance between screw placements of the existing drain. To find the correct kit for you, measure the diameter of the drain from one screw hole to the other. Each floor drain height extension kit includes (1) 1/4" thick plastic drain height extension piece (3) Rubber washers (1) Set of required screws (1) Brief Instructions (3 easy steps)