Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4W-2100 found under Valveregulatingsystem Pressure by Caterpillar Inc. The National Stock Number assigned to this part is 4820016795410, 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 4W-2100.