Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 74521 found under Lever Valve Switch by Vacco Industries. The National Stock Number assigned to this part is 2995010894164, and the Federal Supply Class is 2995 Miscellaneous Engine Accessories Aircraft. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 74521.