Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 687 1 21551 000 012 found under Circuit Breaker by Bae Systems Maritime Services. The National Stock Number assigned to this part is 5925013457550, and the Federal Supply Class is 5925 Circuit Breakers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 687 1 21551 000 012.