This kit is a combination of the Apex Duty/Carry kit for the M&P shield and the Apex Action Enhancement red trigger for the M&P shield. The Action Enhancement trigger directly replaces the factory hinged trigger with a solid aluminum trigger body which reduces pre-travel and over-travel by approximately 20%. It features a smooth face with a center mounted pivoting safety that maintains factory safety values. The Apex Duty/Carry kit for the M&P shield was designed to provide the shield pistol owner a smooth, consistent trigger pull that is approximately 2 lb lighter (based on variations in factory tolerances) with the advantages of shorter over-travel and more detectable trigger reset. However, armorer or gunsmith installation of the ultimate striker block (USB) into the shield slide is strongly recommended. Features: Reduces trigger pull by approximately 2 lb Smooth uptake and reset Reduces pre-travel Reduces over-travel Reduced reset Center mounted pivoting safety maintains factory safety values