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. - 2-piece solid steel design - Strong and lightweight - Compatible with Ruger firearms that feature the proprietary Ruger integral mounting system - Backed by the unconditional Burris Forever Warranty - 410991 Compatible with Number One 77/22 77ML 77/44 Mini 14 RedHawk