The Mechanical Recoil Reduction System is a direct replacement for the stock recoil rod and does not change the configuration of the gun.
Mechanical Recoil Reduction System Arex Rex Zero 1 Standard Size
The third spring which is contained within the rod controls the movement of the slide so it never rams on the frame.
The package includes 1 Mechanism, 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, the medium/medium and the short is light so the shooter can fine tune the pistol on the opening and locking positions (slide on the battery) according his/hers personal standards.