Precision-engineered Wolff Gunsprings designed for Smith & Wesson revolvers across all major frame sizes. This 14LB Reduced Power Rebound Spring ensures optimal trigger reset in J-frame models (31-940 series), K-frame variants (10-648 series), L-frame revolvers (581-696), and N-frame firearms (24-657 series). Single spring package delivers consistent performance and enhanced trigger control. Part# 16664 represents Wolff's commitment to superior aftermarket components for discerning firearm enthusiasts.