Floor drains in ABS, PVC, cast iron and nickel bronze, mostly adjustable, with solvent weld and no-hub connections.
Adjustable drains are the volume item because they absorb error. The strainer sets independently of the drain body, so the finished floor can land anywhere in the adjustment range without the rough-in being exact — and the rough-in is set long before anyone knows the final floor thickness.
Every floor drain needs a trap, and a trap in a room nobody uses dries out and lets sewer gas in. That is what trap primers are for; on a rarely used drain, a primer or a trap-seal device is not optional equipment.
Strainer material follows exposure. Nickel bronze is for finished floors where the grate is visible and gets walked on; plastic is for concealed or utility locations. The grate's free area also matters — a decorative pattern with little open area drains far slower than the pipe can carry.
Brands include Sioux Chief and Zurn.
