The RYG Stainless Steel Guide Rod fits all G20,21,21SF Pistols. This price includes the stainless steel guide rod, 3/32 allen wrench and set screw. The recoil spring must be purchased separately. Recoil springs can be purchased HERE. RYG stainless steel guide rods provide a decisive advantage for all Glock owners. Special features include a rigid stainless steel body that improves lock up by completely removing "guide rod flex". The hex screw removable tip allows the user to choose various spring weights that will calibrate the ammunition to his gun. Used by Law Enforcement and competitive shooters world wide, will not chip or crack like the factory plastic guide rods are prone to do. Will not damage or wear your polymer frame and guaranteed to provide a lifetime of reliable service. We recommend the use of Blue Loctite on the hex screw threads. This will provide a firm hold and still allow easy removal when necessary.