Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S4444978-18 found under Packing Preformed by Boeing Aircraft. The National Stock Number assigned to this part is 5330005855953, 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 S4444978-18.