The piston head itself is composed of 4 separable parts: the rubber piston head face, the piston head base, the thrust bearing, and the piston head support.
The rubber piston head face is surprisingly easy to remove from the piston head base, revealing a metal center shaft.
The rubber piston head face provides an additional ~3mm of cushioning, and is shaped to conform to the contoured funnel of the cylinder head. 6 ports are cut into the piston head face and base so as to facilitate cylinder filling, as with the standard ported piston head design.
