For accurate study of forces, vectors etc. Sturdy construction. Aluminum Metal Table Top (not wooden which can warp) 40 cm in diameter, graduated in degrees, supported by a metal pillar. Metal tripod base, 16 cm long with leveling screws. Supplied complete with, Centering Pin, four Clamp Pulleys, Centering ring with threads and hooks, four Slotted Weight hangers 100 gm, four set of 8 slotted weights, 2 of 100 gm, 3 of 50 gm, 2 of 20 gm and one of 10 gm.