This stroke Wheel comes with Cam, Bearing and screw, ready to be installed in your MotorBolt. Changing stroke wheels will change the needle displacement. Your XionS comes with the 1.8 and 2.5 so this stroke wheel will allow you to hit the skin harder. The stroke wheels are easily interchangeable. This may be used for areolas, skin needling or any procedure that you want more out of your XionS.