Ruger .22 Target Pistol Scope Base Adapter 90224 allows you to mount a scope to your .22 target pistol. Designed specifically for the Ruger Mark I, II, and II .22 caliber pistol, this riflescope base provides a secure mounting platform for Weaver-style rings, allowing you to increase your accuracy with your Ruger .22 pistol. Though the Ruger .22 Mark I, II, II Scope Base Adapter isn't compatible with Ruger rifle scope rings, you can screw on a variety of other rings to your .22 pistol using the mount's three screws.