Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 40X3-4-100PSI found under Valve Relief Pressure And Temper by Bauer Inc. The National Stock Number assigned to this part is 4820005418839, 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 40X3-4-100PSI.