Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S-521000-00 found under Computer Digital by Sierra Video Systems Inc. The National Stock Number assigned to this part is 7021016165485, and the Federal Supply Class is 7021 Adp Central Processing Unit Cpu Computer Digital. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S-521000-00.