Apex Tactical Specialties SD Spring Kit. Reduced trigger pull weight by approximately two pounds compared to the factory the Apex Spring Kit reduces overall trigger pull weight. The springs included in this Firearm Spring Kit from the experts at Apex Tactical Specialties are designed for duty/carry use and are designed to be used as a stand-alone or in conjunction with the Apex SD Polymer Action Enhancement Trigger. For a great way to improve your Smith & Wesson SD & SDVE Series semi-auto pistols choose the Apex Tactical Specialties Firearm Spring Kit. Specifications for Apex Tactical Specialties SD Spring Kit: Manufacturer: Apex Tactical Specialties Gun Model: Smith & Wesson Sigma Smith & Wesson SD VE Condition: New Package Contents: Apex Tactical Specialties SD Spring Kit What firearm models does the manufacturer say Apex Tactical Specialties SD Spring Kit is compatible with? The manufacturer says that Apex Tactical Specialties SD Spring Kit is compatible with Smith & Wesson Sigma Smith & Wesson SD VEApex Tactical Specialties 107-120: SD Spring Kit