The Apex M&P Competition Action Enhancement Kit was designed for the action shooting sports competitor. This drop-in kit will reduce trigger weight by approximately 4.0 lbs. (based on a starting trigger pull weight of 7.0 to 8.0 lbs.). The competition striker spring and trigger return spring are shot-peened to extend service life. The kit is engineered to be drop-in and should not require further gunsmithing (however, armorer or gunsmith installation is recommended). The M&P Competition Action Enhancement Kit is perfect for use with the M&P already equipped with the Apex Polymer or Aluminum Action Enhancement Trigger.