Make: Harley Davidson OEM Air Filter Air Flow: 46.24 CFM DNA Air Filter Air Flow: 137.30 CFM DNA Increased Air Flow: 196.96% DNA Filtering Efficiency:98-99% Product Information This 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 Harley Davidson workshop manual. The filtering efficiency is extremely high at 98-99% filtering efficiency (ISO 5011), with 4 layers of DNA Cotton. The flow of this DNA Fcd filter is high, 196.96% more than the Harley Davidson stock paper filter! DNA Fcd air filter flow: 137.30 CFM (Cubic feet per minute) @1,5"H2O corrected @ 25degrees Celsius. Harley Davidson stock paper filter: 46.24 CFM (Cubic feet per minute) @1,5"H2O corrected @ 25degrees Celsius This DNA filter is designed as a High flow Air filter for: Road and Off road use.