Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 688-6800 found under Protector Telephone by Northern Telecom Systems Corp. The National Stock Number assigned to this part is 5920010178720, and the Federal Supply Class is 5920 Fuses Arresters Absorbers And Protector. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 688-6800.