The Superior Tool Plumber's Pal Fits Hex Drains & All 4- 6- & 8-tab Locknuts. Fits All Drop-in Shower Drains. Patented design fits hex nuts and all 4-, 6- and 8-tab locking nuts on strainer drains. The square end of the tool is specifically designed for tightening stand-up shower drains. It fits into the internal locknut slots of all major manufacturer’s plastic and brass drains.