The CCO combines an Officer-grip Aluminum frame with a Commander-length slide. The shorter"" compact Officer-sized grip aids concealed carry and minimizes the chance of printing under a cover garment. This pistol is chambered in 45ACP with a 4.25"" button rifled barrel supported by a full length guide rod. Includes a dovetail fiber optic front sight and LPA MPS1 type adjustable rear sight. Also includes skeletonized hammer and trigger. The Rock Ultra CCO is finished with a tough Parkerized/Anodized coating and adds a battle ready G10 tactical grips. True to all Rock Island 1911s. the Rock Ultra comes with a crisp factory 4- to 6- pound trigger to give you a great experience right out of the box.