Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 12-490 found under Plate Arm by Smyth Mfg Co. The National Stock Number assigned to this part is 3610000431513, and the Federal Supply Class is 3610 Printing Duplicating And Bookbinding Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 12-490.