This blank (undrilled) baseplate accepts any ITG JC50 Large Dual Carburetor Megaflow Air Filter (Part No. 3817-050, sold separately). It is ready for you to drill to match whatever intake pattern you have. Includes three filter element mounting clips. Sold individually.
The ITG Megaflow JC50 filter measures 5.8" wide x 17.2" long, with a red plastic band around the top and bottom of the filter element.