Flexible, rubber, unshielded sewer couplings connect Clay, CIT, Extra Heavy Cast Iron, Schedule 40 Plastic or Thinwall Plastic pipe to Clay, CIT, Extra Heavy Cast Iron, Schedule 40 Plastic, Thinwall Plastic, CIT, Trailer, or Drain (EPDM) pipe in sanitary systems. For non-pressure, gravity flow applications only. Recommended for underground installations. Primarily used in the Eastern United States. Easy to install and reuse.