Black Swan's Closed Cell Gasket - Wall Hung Closet is an expanded closed cell chemical resistant foam gasket used to make seal between wall and closet. Especially designed to eliminate the leakage often encountered with inferior foam rubber gaskets. Size of gasket is 5-1/4” O.D. X 3-1/2” I.D. X 5/8” HIGH. It is resistant to water, petroleum products, chemical and similar substances. Will not rot.