OATEY Toilet Flange Extension Kit, corrects flange elevations ranging from 1/4" to 1-5/8" Will work for any new installation or repair on an existing toilet flange Extends from 1/4 to 1-5/8 to Finished Floor. Use spacers on top of your existing flange " Designed to snap-in-half, allowing you to slide the spacer underneath your raised toilet flange ring and support your toilet bolts Also used as a layout tool for installing new toilet flanges Made of durable plastic.Set-Rite can be used on existing PVC, ABS, Cast Iron and Stainless Steel ringed flanges"