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.