Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M39 019 03 312 found under Circuit Breaker by Sensata Technologies Inc. The National Stock Number assigned to this part is 5925012843170, 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 M39 019 03 312.