Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number E-57-3BZ-.50IN-PC7 found under Regulating Element by Ernst Flow Industries Inc. The National Stock Number assigned to this part is 4820015486978, 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 E-57-3BZ-.50IN-PC7.