Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 11-10638 found under Filter Element Flui by Western Filter A Division Of. The National Stock Number assigned to this part is 2940015240015, 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 11-10638.