Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 5N2178 found under Valve Flow Control by Caterpillar Inc. The National Stock Number assigned to this part is 4820012735499, 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 5N2178.