Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2681A found under Header Assembly Heater Duct by Stewart And Stevenson Power Products. The National Stock Number assigned to this part is 2990003132138, and the Federal Supply Class is 2990 Miscellaneous Engine Accessories Nonaircraft. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 2681A.