flexon toilet flange for 4" pvc, abs, cast iron or lead pipes-includes spacer system to correct flange elevation from 3/8"-1 1/8" coflex the flexon flange is the best new solution to install or replace a toilet flange. the inward seal eliminates the need for a wax ring and provides an hermetic seal to the toilet horn. additional seals on the sleeve seal to the interior of the pipe. the spacers included are covenient for lifting the flange to the finished floor level when needed. compatible with 4" pvc, abs, cast iron or lead pipes. additionally, the patented toilet seal gauge included allows the installer to check if a secure seal is made before lifting and setting the toilet on the flange.