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