The ZEV Tech Stainless Steel Guiderod is a direct factory replacement for easy spring changing capabilities and increased longevity over stock. FACTORY SPRING NOT COMPATIBLE. Please also check the ZT-Washer. The guiderod can be used uncaptured, but you'll find it more comfortable with the washer having spring and guiderod in one unit like the factory recoil spring assembly. Most people come back for this, you might as well save freight etc.