The True Precision Recoil Spring Tuning Kit enhances the performance of your Sig Sauer P365-FUSE 4.3" pistol with precision-engineered springs made from high-strength chrome silicon for consistent function and extended service life.True Precision Recoil Spring Tuning Kit for P365-FUSE 4.3" ModelsHigh-strength chrome silicon construction for durabilityIncludes four spring weights: 10-LB 12-LB 14-LB and 16-LBStainless steel non-captured guide rod with screw and bushing includedDesigned for compensated/suppressed applications100% Made in the USAPerfect for fine-tuning your pistol's recoil characteristics cycling performance and compatibility with different ammunition loads. Multiple weight options allow you to dial in the perfect feel for your specific setup and shooting preferences.