Rival Arms Optic Ready Slide A1 Sig P320 Carry RMR Cut QPQ Black 416R Stainless Steel The Sig Optic Ready Slide Is a Match-Grade Precision Upgrade Slide With Front & Rear serrations For Easy Slide manipulation. It Is CNC machined From 416 Stainless Steel With recessed Slide cuts For Compatibility With RMR Or Other Optics. This Slide Also Has QPQ Thermo-Chemical Finish, Window cuts For Efficient cooling & Airflow. Model: Optic Ready Slide Material: 416R Stainless Steel Finish: QPQ