The Apex M&P Duty/Carry Action Enhancement Kit for the M&P 9mm, .357Sig, & .40S&W handguns is engineered to provide a consistent 5.0 to 5.5 lbs trigger pull. The Apex Action Enhancement Kit gives the advantage of shorter over-travel and shortened trigger reset. All of the Apex M&P Duty/Carry Action Enhancement Kit components work together to provide a pull weight within the acceptable range for a top end, service pistol. The kit itself is engineered to be drop-in and should not require further gunsmithing (however, armorer or gunsmith installation is recommended).