Apex Tactical Specialties Duty/Carry Kit for the S&W M&P Shield. All of the components work together to provide a pull weight within the acceptable range for a top end service pistol. However armorer or gunsmith installation of the Ultimate Striker Block (USB) into the Shield slide is strongly recommended. Expected Results - Reduces trigger pull by approximately 2 lbs. - Smooth uptake and reset - Reduces reset length - Reduces over-travel Notes If you are interested in a replacement trigger for the M&P Shield please see the Shield Duty/Carry Action Enhancement Trigger and Kit. For further information regarding the trigger itself please see Shield Action Enhancement Trigger. The Shield sight removal in order to install the USB Kit is extremely difficult. Removal requires delicate precision so as not to damage the sights or slide. We highly recommend having a competent gunsmith perform this task. Specifications for Apex Tactical Specialties Duty/Carry Kit for the S&W M&P Shield: Manufacturer: Apex Tactical Specialties Gun Model: Smith & Wesson M&P 40 Shield Smith & Wesson M&P 9 Shield Package Contents: Apex Tactical Specialties Duty/Carry Kit for the S&W M&P Shield What firearm models does the manufacturer say Apex Tactical Specialties Duty/Carry Kit for the S&W M&P Shield is compatible with? The manufacturer says that Apex Tactical Specialties Duty/Carry Kit for the S&W M&P Shield is compatible with Smith & Wesson M&P 9 Shield Smith & Wesson M&P 40 ShieldApex Tactical Specialties 100-076: Duty/Carry Kit for the S&W M&P Shield