The Spectre knurled outer-edge Universal Air Cleaner Nut is cut from billet steel and triple chrome plated for a lasting shine, ensuring that it performs as well as it looks. This universal air cleaner nut fits all 1/4 inch 20 threaded studs and can be used on many aftermarket air cleaners and plenums. The knurled outer-edge design provides a sure grip when removing and installing the air cleaner lid, ensuring optimum fit and function.