Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 56MD39M found under Gasket by Mack Trucks Inc. The National Stock Number assigned to this part is 5330016968865, 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 56MD39M.