SUPERB QUALITY DNA HIGH FLOW AIR FILTER FOR CRF1100L /ADV 2020 2021. DNA replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. These filters are washable and reusable and are custom designed to fit into your existing factory air box. Their drop-in design means adding performance is simple. They offer bigger air-flow, with almost 99% filtering efficiency. It’s ideal for Honda CRF 1100L Africa. OEM Air Filter Air Flow. DNA Air Filter Air Flow. DNA Increased Air Flow. This set, consists of two filters and features DNA’s Advanced FCd (Full Contour design). To install this new DNA Air filter follow the installation instructions included in the workshop manual, and check installation info written on the DNA filter. The filtering efficiency 2 is extremely high at 98 – 99% filtering efficiency (ISO 5011), with 4 layers of DNA ® Cotton. The flow of this DNA filter is 45.63% more than the stock filter. This DNA filter is designed as a High flow filter for Road & Off-Road use.