Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1673A found under Heater Immersion Liquid Fuel Fir by Vilter Mfg Corp. The National Stock Number assigned to this part is 4520012804668, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 1673A.