Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 402-2639 found under Nut Regulator Mnt by Abrasive Blast Systems Inc. The National Stock Number assigned to this part is 4820015005639, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 402-2639.