The Zurn Z550 9" medium-duty drain comes with a Dura-Coated cast iron body with bottom outlet, seepage pan, and combination membrane flashing clamp and frame for medium-duty, cast iron, heel-proof slotted grate.
Floor drains are typically sized based on the flow rate that can pass through the attached piping. The Z550 features a grate with 18 square inches of open area, while an 8" pipe has roughly 50 square inches of open area. In this case, the grate would severely restrict the flow to the 8" pipe. When a similar drain is needed for 8" pipe, specify the Z505.