Spectre's Small Air Cleaner Nut Billet O-Ring fits the majority of 1/4 inch-20 carburetor bolts, studs and screws. This billet universal air cleaner nut is cut from billet steel and triple chrome plated for a lasting shine. Designed to perform as good as they look, the O-ring outer edge design provides for a sure grip when removing and installing the air cleaner lid.