DNA Air Filters - Air Filter for BMW R 1200 GS 02-12 / R 900 RT 03-13 / R NineT 15-20This filter features DNA's advanced FCd (Full Contour design). Installation of the filter is very easy, simply follow the information that can be found in the BMW workshop manual. The filtering efficiency is extremely high at 98 99% filtering efficiency, with 4 layers of DNA Cotton. The flow of this DNA Fcd filter is very high, 104,90% more than the BMW stock paper filter! DNA Fcd air filter flow: 122,10 CFM (Cubic feet per minute) @1,5"H2O corrected