The Heavy Tungsten Guide Rod uses the same factory weight springs except on a tungsten body which is significantly stronger and heavier than the factory plastic guide rod. The Glockstore Heavy Tungsten Guide Rod Assembly improves accuracy and speed as well as reduces recoil and muzzle flip. Springs are captured on the guide rod assembly, completely assembled, ready to drop in and shoot. Installs in seconds, no gunsmithing or tools 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.