Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2-21251 found under Hub Fan Clutch by Gkn Rockford Inc. The National Stock Number assigned to this part is 2930011525532, and the Federal Supply Class is 2930 Engine Cooling System Components Nonaircraft. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 2-21251.