OPTILOCK scope mount rings and bases are precisely machined out of solid steel to ensure perfect mating with our integral receiver scope mount rails and optimal scope alignment. OPTILOCK‚ scope mount rings come clamshell-packed in pairs. Hex key included. OPTILOCK‚ scope mount rings are available in two diameters and four heights. Three lowest rings are also available in stainless steel. OPTILOCK‚ scope mount rings feature a patented spherical fastening ring which makes scope mounting considerably easier. This protective sleeve also ensures that the scope body will not be scratched or damaged during mounting. Appropriate ring height for Sako and Tikka rifles can be determined with the help of the following chart. The maximum scope objective lens diameter (or diameter of scope-lens cover) that can be used with the scope mount in indicated in the column ‚Scope outer max. dia. The larger value can be used with standard-contour barrels, while the smaller number should be used with heavy-barreled models (such as varmint rifles).