Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AAU-27 A found under Altimeter Pressure by Aeronautical And Support Equipment. The National Stock Number assigned to this part is 6610004681958, and the Federal Supply Class is 6610 Flight Instruments. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like AAU-27 A.