Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number MS21916D16-12 found under Reducer Boss by Dana Inc. The National Stock Number assigned to this part is 4730006401306, and the Federal Supply Class is 4730 Hose Pipe Tube Lubrication And Railing Fittings. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like MS21916D16-12.