Plumber's Putty
Plumber's putty is the first line of defense against leaks. A piece about the size of your little finger is placed around the tub strainer insert. The insert fits into the drain hole in the tub.
Rubber Gasket
A thick rubber gasket completes the seal on the underside of the tub. It goes over the drain insert before threading the insert into the elbow portion of the drain line, also called the drain waste shoe or ell.
Leak-Free Assembly
The strainer insert is installed with a tub wrench or a pair of pliers. Tightening the strainer squeezes the plumbers putty into the tub drain opening around the insert, forming a leak-free seal.