Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 56C106C4 found under Spring Valve by Allen Aircraft Products Inc. The National Stock Number assigned to this part is 4820011664130, 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 56C106C4.