Been runnin Twin air filters since the 90s. They are one of the very best filters you can use. Another great point is they have excellent customer service! Be advised though, only use twin air oil and cleaning products. I used another brand and bagged it for future use (spare) and it fell apart upon removal. Also, Motosport take note, I have brought this to your attention in the past. Power Flows Do NOT come pre oiled as advertised - "Filters are pre-oiled with Twin Air BIO Foam Filter Oil using state of-the-art filter oiling machines to provide the ultimate consistency in pore coverage".