Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3-56-1A found under Seal Plain Encased by Oldenburg Group Incorporated. The National Stock Number assigned to this part is 5330010913321, 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 3-56-1A.