Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M534A4-20 found under Retainer Packing by Cam Fabricated Systems Inc. The National Stock Number assigned to this part is 5330001534532, 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 M534A4-20.