Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A1321-26 found under Fan Centrifugal by Singer Co The. The National Stock Number assigned to this part is 4140000814364, and the Federal Supply Class is 4140 Fans Air Circulators And Blower Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like A1321-26.