Installation of this kit reduces trigger pull weight of your centerfire J-frame Smith & Wesson revolver from over 12 lbs to 9 lbs Kit contains a new rebound slide spring, main spring, and an Apex XP firing pin kit Installation requires no fitting or modification to the factory springs or parts Just remove the factory parts and install the j-frame duty/carry kit Works with all modern centerfire J-frame revolvers with the frame mounted firing pin Mfg: Apex Tactical Specialties Inc