Every pair of Element Accu-Lite rings begin its life as a single block of 7075-T6 Aluminium, which has a strength-to-weight ratio superior to almost any other alloy. This block is CNC machined to the tightest tolerances to ensure a smooth and precise mating surface between the riflescope body tube & base. Add to that a Stainless Steel cross bolt, base clamp & nut, and you have one of the most precisely built, reliable ring sets on the market. A good ring set is critically important, as it is the only point of connection between your rifle and riflescope.