D-R2 for retrofit in 2-8" floor drains. Dranjer seals permit unrestricted flow of water into floor drains or sump pits while sealing out the entry of mold spores, insects, radon and other gases from the sub-slab floor area. A flexible rubber flange is attached to the hard plastic portion of the seal. Hold the Dranjer under the existing strainer plate. Push the strainer plate with the Dranjer back into the drain opening. Friction among the sides of the cover plate, the unit, and the ring in the floor holds the Dranjer under the cover plate. Trim off the rubber that extends past the strainer plate. You have retrofitted the Dranjer D-R2 Fits drain pipes 2? or larger.