This island tub drain quickly and easily installs free standing bathtubs from above the floor. The drain attaches to 2 In. sch 40 pipe and mounts to a 2 In. p-trap in the floor for sewer gas retention. The drain also comes with a 2 x 1-1/2 In. reducer bushing to accomplish the same task in the smaller size. The drain easily mounts in the sub floor using a 3-7/8 In. (98 mm) hole saw. Drill through and attach with the included stainless steel screws to securely mount it in place. Each model comes with silicone grease and a choice of a 1-1/2 In. threaded or top hat style 17 ga brass nipple for tub mounting. Every model comes with a dust cap and pressure testing plug for leak testing.