DPM Glock 20/21/40/41/41SF Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil System Gen 4. The system offers almost double force at the end of full open position of the slide. Compared to the factory OEM spring provides additional force that stops the violent rams on the frame. From the above effect the slide stops smoothly on the frame and offers less recoil. Lastly the moving parts of the pistol are protected offering longer life to the pistol. 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 Glock 20/21/40/41/41SF Gen 4 Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil System: Manufacturer: DPM Fabric/Material: Spring Steel Gun Make: Glock Gun Model: Glock 41SF Glock 41 Glock 40 Glock 21 Glock 20 Features of DPM Glock 20/21/40/41/41SF Gen 4 Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil 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 Glock 20/21/40/41/41SF Gen 4 Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil System What firearm models does the manufacturer say DPM Glock 20/21/40/41/41SF Gen 4 Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil System is compatible with? The manufacturer says that DPM Glock 20/21/40/41/41SF Gen 4 Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil System is compatible with Glock 20 Glock 21 Glock 40 Glock 41 Glock 41SFDPM MS-GLG4/5: Glock 20/21/40/41/41SF Heavy Duty ++P Loads Captured Version Mechanical Heavy Duty Captured Recoil System Gen