This kit comes with either a 10 tooth sprocket for a 40/41 chain or a 12 tooth sprocket for a 35 chainThis asymmetric torque converter design has been very popular the past 30 yrs, and has been used on many different brands of 5 - 9 HP small engines, Go Karts, and Mini Bikes. This unit replaces Comet 218353A, 219552A, 219456A, 203814A, and 217610A TAV2 30-75 Torq-A-Verters, and can be used as a replacement for nearly all go kart and mini bike manufacturers like Yerf Dog Driver Unit Q43201W, Manco, American Sport Works, Kartco, Road Boss, Thunderkart, Clipper, Ken-Bar, TrailsportCarter Brothers, Cushman Scooters, Yerf Dog Go Karts and more.