This part is the replacement drain check valve for your dishwasher. It is made of black plastic and is approximately 1-1/4 inches by 1-1/4 inches. The round section of the check valve is approximately 1 inch in diameter. The drain check valve prevents dirty water from re-entering the dishwasher once it has been pumped out. If the check valve is damaged or missing, you may notice that your dishwasher is not cleaning the dishes properly. This part is sold individually and is an authentic OEM part sourced directly from the manufacturer.