DPM Captured Recoil Reduction System Ruger RXM 4in. The two visible external springs are designed to serve each setup and the ammunition used. Package Contents: DPM Captured Recoil Reduction System What firearm models does the manufacturer say DPM Captured Recoil Reduction System is compatible with? The manufacturer says that DPM Captured Recoil Reduction System is compatible with Ruger RXM Glock 44 Glock 31 Glock 37 Glock 17 Glock 22 Glock 34 Glock 35 Glock 19DPM MS-RU/7: Captured Recoil Reduction System Ruger RXM 4in