Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number C158B-4 found under Stem Fluid Valve by Henry Technologies Inc. The National Stock Number assigned to this part is 4820012970061, 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 C158B-4.