This Kensight Bo-Mar Rear Sight is Fully Adjustable for both windage and elevation, and is an excellent upgrade for any 1911 or other pistol that is equipped with a Bo-Mar BMCS style rear sight dovetail. The rear sight body is Wire-EDM machined from 4140 Chrome Moly Steel that is then heat treated to a hardness of RC 38-40, ensuring tight part-to-part fit and long-lasting durability. Click-adjustments are positive and precise, allowing for reliable and consistent point of impact changes. This Bo-Mar Rear Sight is equipped with a Square Target Blade that is Fully Serrated to reduce glare, and incorporates Kensight's special Deep Sight Notch that is cut 0.020" deeper than standard for faster, more intuitive acquisition of the front sight post. Notes: Blade Notch Dimensions: 0.135" Wide x 0.120" Deep Sight Body Dimensions: 1.407" x 0.689" x 0.413"