Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 12890-503 found under Coupling Shaft Flexible by Elliott Company. The National Stock Number assigned to this part is 3010010659908, and the Federal Supply Class is 3010 Torque Converters And Speed Changers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 12890-503.