Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 144US139 found under Push Button by O F Mossberg And Sonsincorporated. The National Stock Number assigned to this part is 5930004570507, 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 144US139.