An economical and practical kit that provides a complete selection of scope shims. When "just a little more" height is needed for perfect scope base and ring alignment. Mfg: Brownells SPECS: Steel, blued. Kit contains 10 of each hole spacing and thickness (80 total). Available in .600" (15.2mm) and .860" (21.8mm) c-to-c hole spacing and .006" (.152mm), .008" (.203mm), .010" (.254mm), .012" (.304mm) thickness. Refills sold 10 each per pak.Check price and Read more Detail At Brownells