The Heavy Tungsten Guide Rod is three times heavier than the factory plastic and almost twice as heavy as the stainless steel guide rod. The extra weight of the tungsten guide rods for your subcompact Glock helps the gun shoot better and feel better. You'll be able to shoot faster and more accurately while reducing recoil and muzzle jump. It's a drop-in part with the dual springs included and captured on the rod. The Heavy Tungsten Guide Rods drop in easily without any gunsmithing required. NoteGlockstore Heavy Tungsten Guide Rods weigh roughly 52-58 grams as compared to stock guide rods which weigh between 12-16 grams. DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.