Complete S-3 Racing Top End Kit. These no longer have the big G logo on the right side anymore since KTM aquired the Name Brand. S-3 Billet Racing Head unfortunately no longer available with set of 3 different domes for tuning purposes. The Extreme dome is the closest to stock compression and squish distance, corrected squish angle for increased cooling, improved combustion and efficiency, increased torque and horsepower. Or you can opt for the higher compression dome if you are going to stack additional base gaskets to alter/tune port timing for high altitude or running race fuel at low-moderate altitudes. The price shown is for one dome only Not 3. Increase compression and reduce squish clearance by changing domes available on request. Dome with least clearance gives highest compression. S-3 piston kit by Vertex (light weight for quick revs and less vibration) includes piston, rings, pin, clips, bearing and top end gaskets required for the kits installation.