Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number ERI3640 found under Rocker Arm Engine P by Optex Systems Inc. The National Stock Number assigned to this part is 2805007974637, and the Federal Supply Class is 2805 Gasoline Reciprocating Engines Except Aircraft And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like ERI3640.