The AEK Trigger is an enhanced trigger for the Smith & Wesson M&P Pistols, reducing trigger pre-travel and over travel by approximately 20%. Unintended operation of the trigger is prevented by the Center Mounted Pivoting Safety bar. This bar creates a block that will not disengage unless the shooter places their finger directly on the trigger face. The flat, smooth face of the trigger encourages the shooter to place their finger on the center line of the trigger, ensuring trigger manipulation directly in line with the bore axis. Included Trigger Return Spring Installation Slave Pin aids in the reinstallation of the trigger return spring. This trig Mfg: Apex Tactical Specialties Inc SPECS: Does NOT fit Shield.