This part is the upper spray arm for your dishwasher. It is made of gray plastic and is approximately 11 inches wide. The upper spray arm is mounted to the top of the dishwasher tub and rotates during the cycle to ensure that your dishes are washed evenly. If your spray arm is clogged or damaged, your dishes may not clean evenly, and you will need to replace the spray arm. To access the spray arm, you will need to remove the top dish rack, then simply unscrew the old arm. Screw the replacement arm in and replace the dish rack to complete the repair.