Located on the lower half of the dishwasher, the lower spray arm rotates and sprays water to clean the dishes in the washer. It does this when water is pushed through the spray arm by the units pump and motor assembly. The force of the water helps rotate the spray arms. If your dishwasher has symptoms, such as unclean dishes, odd noises, lower spray arm not rotating, or water leaking from the bottom of the dishwasher door, then this replacement could be a solution. No tools are required for this simple repair, but make sure to wear gloves for protection during repair.