The Whirlpool W11579392 is an alternative part intended to function as a dishwasher rack stop. It's a tiny but important component that is normally put on the upper or lower dishrack. The rack stop serves as a necessity for holding the dishrack snugly in place while the dishwasher runs its wash cycles.Consider two minimal plastic tabs or hooks on the rack that fit into predetermined slots on the rack stop. When you fully put the rack in, these tabs click onto the rack stop, preventing the rack from becoming loose or dislodged during the washing cycle. This keeps your dishes securely in place and prevents any clattering or impairment throughout the washing process.