Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 500439-1 found under Adapter Flywheel Ho by Metadure Parts And Sales Inc. The National Stock Number assigned to this part is 2990011771001, 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 500439-1.