Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 99551-1 found under Relay by Piasecki Aircraft Corp. The National Stock Number assigned to this part is 5945005296058, and the Federal Supply Class is 5945 Relays And Solenoids. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 99551-1.