The system works due to the multi spring intricate rod (3 springs) and controls the functionality of the pistol and replace the stock recoil with out to change the configuration of the pistol. The third spring which is contained within the recoil rod controls the movement of the slide so it never rams on the frame. This system includes 3 different in length Washers / Spacers. The longer Washer offers a heavy buffer effect, moving to shorter Washer a lighter buffer effect is being offered, so the shooter can fine tune the total force of the spring system according his/hers personal standards depends the type of ammunitions that using. Specifications for DPM Mechanical Recol Gen 5 Captured Version Reduction System: Manufacturer: DPM Color: Stainless Fabric/Material: Stainess Steel Gun Make: Glock Gun Model: Glock 35, Glock 34, Glock 22, Glock 17, Glock 37, Glock 31 Model Generation: 5 Condition: New Features of DPM Mechanical Recol Gen 5 Captured Version Reduction System User adjustability. Captured recoil rod. 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. Easier installation. Package Contents: DPM Mechanical Recol Gen 5 Captured Version Reduction System