Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3781-325 found under Indicator Filter Warning Vehicul by Engineered Products Co. The National Stock Number assigned to this part is 2940012653303, 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 3781-325.