Comes in Plastic, Aluminum, or Titanium. Plastic -- Gives you an extra point of Tuffness and makes your bones unbreakable under normal stresses. A car-crusher could still break them, but they won't break from a terminal- velocity fall or anything you can do with muscle strength. Adds 25 pounds to weight. So that's 7 points (bone-breaking is a special effect, so it's free) but might come with a disad involving heavier natural encumbrance if those 25 lbs. push you over the edge. Aluminum -- as above, with more Tuffness bonuses and a ST boost. Titanium -- as above, with still more Tuffness bonuses and a ST boost. See the ShadowTech book for more details.