Vertex Piston Kit - Standard Bore 46.94mm 24212AExact fit A, B, or C pistons match your cylinder bore perfectly to maximize power and performance while reducing blow by and oil consumption 2 stroke pistons have an 18% silicon content which decreases wear and thermal expansion, allowing for tighter running tolerances for more power, less noise, and longer lifespan High tech Molybdenum Disulphide (MOS2) skirt coating for reduced wear and improved break in 4 stroke pistons are forged from either 2618