Springfield PX9119LAOS: The Ronin AOS in 9mm combines a legacy of service with modern features. Built for strength, the Ronin features forged steel slides and frames carbon steel in the slide and stainless steel in the frame and a hammer-forged barrel for lasting durability. It includes a standard 5\" barrel with a traditional recoil spring assembly and barrel bushing. Enhanced with AOS, the Ronin employs a series of plates fitting popular optics like RMR, Shield, Delta Point Pro and Docter. Each AOS plate integrates a rear sight, ensuring proper optic height, an intuitive sight picture.