This DNA 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 Aprilia 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, 30.00% more than the APRILIA stock foam filter!DNA Fcd air filter flow: 152.9 CFM (Cubic feet per minute) @1,5"H2O corrected @ 25degrees Celsius.Aprilia stock foam filter: 117.6 CFM (Cubic feet per minute) @1,5"H2O corrected @ 25degrees Celsius.This DNA filter is designed as a High flow filter for road and off road use.