Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 240-080556 found under Valve Check by Cerberus Pyrotronics Inc. The National Stock Number assigned to this part is 4820013436071, 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 240-080556.