Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 55401D found under Cover Synchro Receiver Mount by Symmetricom Inc. The National Stock Number assigned to this part is 5990015307476, and the Federal Supply Class is 5990 Synchros And Resolvers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 55401D.