Clean up the engine bay of your 2001-2021 Duramax with this Billet Aluminum Anodized Oil Fill Cap from WCFab. This is a complete cap, not a cover. Direct OEM replacement for the factory plastic part. Includes o-ring seal and machined cam lock engagement. CNC machined in the USA.-CNC Machined Billet Aluminum GM factory oil cap filler neck replacement -Matches WCFab Billet Aluminum Coolant Tank and Brake Reservoir Caps -Includes o-ring seal -Machined cam lock -Engraved Wehrli Custom logo on bottom of part -Made in USA -Installs in seconds