Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6665603 found under Filter Element Fluid by Melroe Co. The National Stock Number assigned to this part is 2940014713641, and the Federal Supply Class is 2940 Engine Air And Oil Filters Strainers And Cleaners Nonaircraft. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 6665603.