- 1911 Style Thumb Safety for Ruger Mark IV 22/45. Replaces factory thumb safety without modifying the internals, and improves hand placement for better grip and control. - This oversized, 1911-style safety ledge enhances the external factory safety. It's a drop-in part, is easy to install, and does not change the internal components of the gun. Installation of the "Cornerstone" MKIV 22/45 safety ledge is also a great opportunity to remove the factory ambidextrous safety, which can pinch some users' fingers while shooting.
Please note: The "Cornerstone" installation utilizes a factory spacer included in your original box (see pic above). This part is on Page 23 of the original Ruger® manual. If you have misplaced this spacer, please contact TANDEMKROSS or Ruger® to assist you with locating one.