OS&B ITD35 Freestanding Bathtub Rough-In Kit Brass Tail Pipe and ABS Plastic Adapter ITD35 is a Freestanding tub rough-in kit (install before tile installation) Designed to be installed in an 8"/10" joist space with 1-1/2"/2" p-trap respectively Includes: island drain assembly with 1-1/2 inch DWV ABS tailpiece, cutting template & protective Film over opening keeps out debris during rough-in stage and Supplied with brass tailpieces (threaded and flanged) and ABS waste/overflow adaptor kit Can be installed with waterproofing membrane