This is a Apex Tactical Specialties Trigger known as the S&W J Frame, model JFRMDCSK.
The Apex J-Frame Duty/Carry Spring Kit significantly improves the trigger pull of the J-frame revolver by reducing the trigger pull weight by approximately 3.0 lbs. from factory specifications.
Features:
Reduces trigger pull weight by approximately 3.0 lbs. from factory specifications
Easy to install