DPM Beretta 9000 S Subcompact 9mm/40 S&W. This system works due to the multi spring intricate rod (3 springs) and controls the functionality of the gun. The third spring which is contained within the rod controls the movement of the slide so it never rams on the frame. The longer spring (more coils) is stronger and has a heavier pound rating than the shorter spring. The springs are different in length with the longer being heavier than the short when the slide is on the battery so the shooter can fine-tune the weapon for his/hers personal standards. Always apply the Washer ring when the DPM System is installed. As lead the evolution of recoil reduction technology products may change versions (new design with different springs with or without plugs washers etc.) without any prior notice. Specifications for DPM Beretta 9000 S Subcompact Mechanical Recoil Reduction System: Manufacturer: DPM Fabric/Material: Spring Steel Gun Make: Beretta Gun Model: Beretta 9000S Features of DPM Beretta 9000 S Subcompact 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 Beretta 9000 S Subcompact Mechanical Recoil Reduction System What firearm models does the manufacturer say DPM Beretta 9000 S Subcompact Mechanical Recoil Reduction System is compatible with? The manufacturer says that DPM Beretta 9000 S Subcompact Mechanical Recoil Reduction System is compatible with Beretta 9000SDPM MS-BE/4: Beretta 9000 S Subcompact 9mm/40 S&W