Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number P4S1639-REV-2-ITEM-78 found under by Panelmatic Youngstowninc. The National Stock Number assigned to this part is 5930015765424, and the Federal Supply Class is 5930 Switches. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like P4S1639-REV-2-ITEM-78.