The Rival Arms Glock Guide Rod Assembly is designed to be an upgrade to the factory polymer guide rod on the Gen 3 models listed. Polymer can fail from cracks or breaks and is susceptible to accuracy robbing flex. The Rival Arms design addresses these issues and provides a lifetime of reliable service. FeaturesPremium spring in stock weightFully assembled CNC-machined stainless steel No gunsmithing required 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.