Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M21 9T4 440 found under Circuit Card Assembly by Mitsubishi Electronics America Inc. The National Stock Number assigned to this part is 5998016663527, and the Federal Supply Class is 5998 Electrical And Electronic Assemblies Boards Cards And Associated Hardware. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like M21 9T4 440.