Urethane reinforced extra thick. Up to 20 times stronger than ordinary wax gaskets. Fits 3" and 4" lines, most wall andall floor toilet bowls. Resilient...springs with bowl movement. Permanent...will not rot like fiber or sponge gaskets. Protects... No Seep sleeve protects sealing area...extends bowl into waste line...adds 3 times the power of plain gaskets. Up to 1/2" tolerance in rough-in and bowl setting.