Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RI 5291B 1 found under Retainer Packing by Clyde Bergemann Limited. The National Stock Number assigned to this part is 5330993980844, 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 RI 5291B 1.