DPM Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System Stainless MS A1-5. The third spring which is contained within the rod controls the movement of the slide so it never rams on the frame. The system includes 1 spring plug and 3 different external springs. The spring plug must always be installed when the DPM Recoil Rod and springs are used. The external springs are different in length the long spring is heavy and the short is light so the shooter can fine tune the pistol on the opening and locking positions (slide on the battery). Specifications for DPM 1911 Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System: Manufacturer: DPM Color: Stainless Finish: Black Oxide Fabric/Material: Stainess Steel Gun Make: 1911 Platform Gun Model: 1911 Features of DPM 1911 Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System Faster follow up shots Improved firing speed Slide and Frame Protection Elimination of jams Significant recoil reduction Better double-tap concentration Better control and greater accuracy Package Contents: DPM 1911 Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System What firearm models does the manufacturer say DPM 1911 Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System is compatible with? The manufacturer suggests that DPM 1911 Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System is compatible with 1911DPM MS 1911 A1-5: 1911 Government 5in Barrel & Clones Bushing Only Mechanical Recoil Reduction System Stainless