The Volquartsen Mamba LLV Rear Sight is precision-machined to ensure accurate, repeatable click adjustments for windage and elevation. No fitting required. Uses factory dovetail and locks in place with two set screws. Made of steel. Rear sight notch width is 0.110". Note: Rear sight height differs between Volquartsen LLV and factory Ruger uppers so be sure to order the correct item.