Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 509409 ITEM 26 found under Seal Plain Encased by The Oilgear Company. The National Stock Number assigned to this part is 5330010442844, and the Federal Supply Class is 5330 Packing And Gasket Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 509409 ITEM 26.