Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 421027-1 found under Heat Sink Electrica by Northern Telecom Systems Corp. The National Stock Number assigned to this part is 5999013147418, and the Federal Supply Class is 5999 Miscellaneous Electrical And Electronic Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 421027-1.