Burris' Ruger-to-Weaver base adapter allows you to use Burris Zee Rings to mount optics onto Ruger firearms that feature the proprietary Ruger integral mounting system. The two-piece, solid steel design is strong and lightweight. This model is compatible with Ruger M77 models or Burris' Eliminator laser scope. With this adaptor, you can use Burris Zee rings on your Ruger rifle or handgun. It properly anchors and aligns your scope so you can consistently put rounds on the target.