Availability: 10 in stock
The multi-purpose nut here is the GM part, numbered 11900428. It is catalogued under Nuts & Washers > Nuts.
The photographs on a listing show the actual stock item, so compare the mounting points and the connector or fitting rather than the overall shape.
Match this against the part you are taking off rather than against a photo. If the number is unreadable, send us the VIN and we will confirm it. In stock and sent from the US in one to two business days, free delivery over $59.