Top sprocket, bottom sprocket and chain must be purchased; all available separately, use HY-VO chain PART # 1226-0027 When installed, M8 is geared down one tooth; XF8 is geared to F8 specifications Can be used with stock tensioner Made in the U.S.A 20/49 gearing is recommended for 2.6" lug 153" length tracks; 19/50 gearing is recommended for 162" length and 3" lug 153" length tracks.. SPROCKET HYVO 25T ARC