Minecraft wiki entry for Piston, associated text: Design B (5x3x2) is actually an RST latch, combining the functionality of both the Set/Reset (RS) and toggle (T) latches. Uses regular pistons. This flip flop doesn't use torches for logic so it can work with signals of any length. The dust on level 1 is there to redirect the redstone wire away from block X, which powers the piston. However, this circuit does not have an inverse output.