TandemKross Accelerator Thumb Ledge Features The TandemKross Accelerator Thumb Ledge adds a forward angled surface to the Ruger Mark IV s frame giving the support hand thumb a dedicated place to rest and push into during recoil. That extra contact point helps the shooter maintain a consistent grip shot to shot which is especially useful for new shooters still building their fundamentals on a rimfire pistol. The scalloped texture molded into the ledge increases traction against the thumb so the hand does not slip during rapid strings of fire. At just 0.30 ounces the ledge adds negligible weight to the pistol. Installation is simple and non permanent so the Accelerator Thumb Ledge can be added or removed without gunsmithing or special tools. It is compatible with factory Ruger Mark IV 22/45 lowers as well as TandemKross s own Cthulhu Lower giving owners of either configuration the same upgrade. Finished in black the ledge blends cleanly with most Mark IV builds without drawing attention to itself. For Mark IV owners looking to improve grip control and follow up shot speed the TandemKross Accelerator Thumb Ledge is available for sale at GrabAGun. TANDEMKROSS Accelerator Thumb Ledge Specifications Manufacturer: TANDEMKROSS Model: Accelerator Thumb Ledge Compatible Hosts: Ruger Mark IV 22/45 TandemKross Cthulhu Lower Color: Black Weight: 0.30 oz Available At: GrabAGun