Schmitt Racing piston in a set for 50cc cylinder with 38mm cylinder liner suitable for Simson Moped / Mokick S51, S53, SR50, Simson Schwalbe KR51/2. The difference to the Schmitt piston STT39981 is in the design and the material properties of the piston rings which are in the Schmitt Racing piston set made of chrome-plated steel, flatter and specially hardened. The piston measures 37.97mm and is coated with a special molybdenum coating. The special sliding properties of this molybdenum coating have a positive effect on the "run-in" of the cylinder, also to prevent piston jamming. This Schmitt Racing piston set comes with piston, gudgeon pin, two piston clips and two piston rings.