5L2952 Cap Oil Filler Fits Caterpillar D300E AP-1000 AP-1000B AP-1050 AP-1050BOne New Aftermarket Replacement Oil Filler Cap Fits Caterpillar (Fits CAT) Engines and Equipment This aftermarket replacement oil filler cap (Cap AS Oil Filler) seals and protects the engine oil reservoir on a wide range of Fits Caterpillar (Fits CAT) diesel engines and equipment, preventing contamination and ensuring proper lubrication. The cap threads securely onto the valve cover oil filler tube and is a direct replacement Fits Caterpillar OEM part