Cassette: a bunch of stacked sprockets or gears within the rear wheel of a bicycle with a rear derailleur. There can be between 5 to twelve gears in back again on the cassette. A lot of the performance parts from GX200/ Predator 212 non-hemi will fit In this particular engine https://bikeengine2stroke95876.newbigblog.com/41189231/indicators-on-predator-ghost-mini-trikes-you-should-know