Polymer AEK Trigger Kit The Apex Polymer Action Enhancement Trigger Kit directly replaces the factory hinged trigger with a solid body polymer trigger with a center mounted pivoting safety. The rounded face of the trigger provides a smooth, comfortable surface for the shooter's finger while firing. The trigger also reduces pre-travel by approximately 20% from the factory trigger and is perfect for use in M&P's already equipped with an Apex Comp AEK or Duty/Carry AEK. NOTE: Will NOT function in M&P M2.0 pistols, M&P Shield or Shield M2.0 pistols, or any of the APEX Forward Set Sear and Trigger Kits Mfg: Apex Tactical Specialties Inc Polymer AEK Trigger Kit: Includes Apex Polymer Action Enhancement Trigger, Heavy Duty Sear Spring, Apex Trigger Return Spring Slave Pin.Fits all S&W M&P Semi Auto Pistols in 9mm, 40 S&W, 357 Sig, and 45 ACP. Does not fit the M&P Shield.