The Glockstore Stainless Steel Guide Rod Assembly replaces the plastic guide rod that comes with the factory Glock easily dropping into place in seconds...no gunsmithing required. This performance part will fit Generation 1, 2 & 3 guns and will last longer and provide better cycling action than the factory plastic part. It comes fully assembled and complete with the spring already captured on the the Stainless Steel Guide Rod - just drop it into your Glock!NoteGlockstore Stainless Steel Guide Rods weigh roughly 28 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.