Apex Trigger Poly. Action Enhancement S&w Sd sdve sigma Trigger Pins The dual port USB design allows The dual port USB design allows user to charge up two devices at the same time while monitoring battery voltage EVA Mudsole for Added Comfort and Grounded Insulation Self Cleaning MS 1 Lug Outsole is Excellent in Mud The apex sd polymer action enhancement trigger directly replaces the factory hinged trigger with a solid body polymer trigger with a center mounted pivoting safety The trigger also reduces pre travel by approximately 20% and over travel by 10% when compared to the factory trigger and is perfect for use in sd and sigma pistols already equipped with an apex sd or sigma spring kit