LARGE SLATE/STAINLESS STEEL PIT & PENDULUMS OUR LARGE SLATE PIT & PENDULUM IS MADE OF A REMARKABLE ACRYLIC/RESIN FINISHED TO LOOK EXACTLY LIKE REAL PENNSYLVANIA GREY SLATE. IT EVEN APPROXIMATES THE WEIGHT OF SLATE. THE HEAVY METAL PENDULUM IS MACHINED FROM SOLID STAINLESS STEEL.