Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number R1131-904 found under Packing Preformed by 4 M Company Inc. The National Stock Number assigned to this part is 5330011656581, 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 R1131-904.