Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number H44518-8-8 found under Back Up Ring Prefor by John Crane Inc. The National Stock Number assigned to this part is 5330015264759, 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 H44518-8-8.