Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4001X4039 found under Gasket by Square D Company. The National Stock Number assigned to this part is 5330003019027, 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 4001X4039.