The FMF Rev pipe focuses its power delivery in the middle and upper rpms of the powerband. If you’re running out of power up top, want more time between shifts and do a lot of deep berm or sand riding, the FMF Rev is your pipe of choice. FMF Racing's Tru-Flo stamping process ensures a perfect fit and optimum performance. Dyno and track tested for every application. FITS: YZ 125, 22-25. YZ 125X, 21-25.