The AIP Aluminum Recoil Spring Rod is an enhanced and upgrades spring guide for 4.3 and 5.1 Hi-capa pistols. These are great to add when putting in a new recoil spring as it will increase efficiency and provide a stronger platform for the spring to coil around. They come in many different colors to allow you to customize your 4.3 and 5.1 Hi-capa to your styling.