We start with the finest 6061-T6 billet aluminum, CNC machined it to perfection The assembly is then mated with a 3" tall, USCG approved, high flow, multi-layered stainless steel screened element The top and bottom sections rest solidly on unique standoffs which will not allow the element to be crushed as can happen with common filter elements. Whether you need standard or a custom dimension, each arrestor is built to exacting specifications. There are no sloppy adjustable mounting bases or elongated holes to contend with, just pure perfection. Length is 21-1/2, and width is 10-1/2Available for single or dual carburetor applications to fit most popular Barry Grant, Holley and Edelbrock carburetors. Need a custom center dimension....NO PROBLEM.