The Fernco 4" OD Wax Free Toilet Seal is designed to seal the toilet to a 4" toilet flange installed on 4" drain pipe. Ideal for most 4" Closet Wall Carriers. A strong and flexible to sustain a positive seal. Ideal for wall carriers and floor mounts. Accommodates floors raised above the toilet flange by up to 3/4 inch. Maintains a gas tight seal even when minor movement occurs. Fast, easy installation for a long-term solution .