The model demonstrates the internal structure  and  operating principles of a Wankel engine. It is cut-way to show the internal constructional details. Unlike other engines the rotary piston engine avoids reciprocating parts. The power piston is an arch like triangular rotor which on rotating generates an epitrechoid,  Hand powered motion supplied through a crank demonstrates the moving parts of the engine as a hand crank is rotated.  A simulated spark plug uses a small lamp to indicate the firing point using 2 AA batteries (not included)..All  construction is  of  aluminum and plastic, Mounted on a metal base  with printed diagram and key.