ZEV Technologies ISMI Recoil Spring 17 lb. 40 and 357 model Glock pistols. Flat coil factory style recoil rod spring. Compact model is compatible with compact Glock models (G19) and OZ9C. Specifications for ZEV Technologies ISMI Recoil Spring: Manufacturer: ZEV Technologies Color: Silver Fabric/Material: Stainless Steel Model: Standard Gun Make: Glock Gun Model: Glock 35 Glock 34 Glock 22 Glock 17L Glock 17 Glock 38 Glock 37 Glock 32 Glock 31 Glock 23 Glock 19 Caliber: 9mm Luger Package Contents: ZEV Technologies ISMI Recoil Spring What firearm models does the manufacturer say ZEV Technologies ISMI Recoil Spring is compatible with? The manufacturer says that ZEV Technologies ISMI Recoil Spring is compatible with Glock 19 Glock 23 Glock 31 Glock 32 Glock 37 Glock 38 Glock 17 Glock 17L Glock 22 Glock 34 Glock 35ZEV Technologies ISMI-SPR-REC-17L: ISMI Recoil Spring 17 lb