Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 31 020 12 961 found under Cover Fluid Filter by Mann Hummel Gmbh. The National Stock Number assigned to this part is 2940123463636, 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 31 020 12 961.