Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4PR3 found under Regulator Pressure by Haws Corporation. The National Stock Number assigned to this part is 4820004631295, 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 4PR3.