Apex Tactical Specialties Shield Action Enhancement Trigger And Duty Carry Kit For M&P Shield (9/40 only), Kit Includes - Action Enhancement Trigger, Slave Pin, Fully Machined .45 Sear, Ultimate Striker Block, Striker Block Spring, Talon Tactical Tool, Shield Carry Spring Set, Sear Spring (1/8), Trigger Return Spring, Black Finish 100-051 The Apex Action Enhancement Trigger & Duty/Carry Kit for the M&P Shield (9/40 only) is a combination of the Apex Duty/Carry Kit and the Apex Action Enhancement Trigger. This kit delivers a significantly improved trigger pull in the Shield without compromising safety.