K&N Oval Style Stacks for "Late Type" Hilborn Siamese Stacks - These filters are designed to be used with stock, uncut, Siamesed ram tubes. Comes with removable aluminum top plate. To install, push Ram Tubes through rubber base and clamp at desired height. Oval top plate measures 9"L x 5 1/2"W, total height is 6 3/4". As with all K&N air filters, these are washable and reusable. Simply use K&N oil and cleaner to service your filter.