These universal filler caps are meant to be used for gas tanks on custom motorcycles, hot rods, or anything else. Lowbrow filler caps fit the maxim ‘form follows function’; they are all business.

Machined out of solid aluminum, these vented caps are 1-5/16″-12 thread and the Buna-N O-ring seal is gas and oil resistant and keeps your fluids contained, leak-free. This is a vented cap of our own unique design. The underside of the cap is milled out and a .75″ diameter, sintered bronze breather disc is inserted and then held securely in place with a snap ring. The breather disc allows air to pass both ways while limiting the passage of oil or gas.

Lowbrow filler caps fit our weld-in steel filler bung or aluminum filler bung for custom applications, as well as Cycle Standard, Mooneyes & British Standard brand motorcycle oil tanks. Made in Ohio, USA.