The ACDelco is a short, pleated paper fuel inlet filter with a built-in check valve designed for1970s-1980s GM vehicles using Rochester Quadrajet carburetors. It measures approximately 1.03 inches in length and 0.72 inches in diameter. It prevents debris from entering the carburetor and manages fuel backflow. 
AMERICAN MOTORS 1980-1983
BUICK 1976-1982
CADILLAC 1980
CHEVROLET 1968-1987
GMC  1976-1988
JEEP 1980-1983
OLDSMOBILE 1976-1982
PONTIAC  1976-1983