DNA Air Filters - Stage 3 MK3 for Honda Monkey 125 - Billet TopStage 3 Kit MK2 version Derlin CNC machined including a pair of DNA hexagon filters. The filtering efficiency is extremely high at 98 99% filtering efficiency, with 4 layers of DNA Cotton for maximum engine protection. The flow of the DNA Stage 3 Air Box Kit is: +103. 70% for the AK H1N19 S3 MK2 more than the Honda stock air box, at 685. 80 LTR MIN @ 10 mBar. This DNAStage 3 Air Box Kit is plug & play with no modifications needed on the throttle body