There is a groove on the back of the part for the HD O-ring gasket

Gold Plated Deluxe - 1999-2007 Fuel Door adds a distinctive custom detail to the motorcycle console with precision-machined artwork and a premium decorative finish

7 ¾ inches in diameter combines precision engraving with a durable premium finish for riders who want their motorcycle to reflect their style

Please check your existing derby cover to confirm that it is 7 ¼ inches also

Milw 8 Timing Cover combines precision engraving with a premium finish for riders who want their motorcycle to reflect their style

Tribal Cross I-04, TC Timer Cover Navy Seals Trident There is a groove onThe Tribal Cross I 04, TC Timer Cover combines precision engraving with a premium finish for riders who want their motorcycle to reflect their style, service, or personal story. Product Details This is a billet machined part that is made to replicate an original Harley Davidson timer cover. Custom Engraving Ltd is the manufacturer in Wisconsin, and we make 1,000s of timer covers every year. Automotive grade PPG paint is used for a durable color