That is called the "Hand", BTW. I'm sure that someone with more experience will explain to you how to replace it on the trigger. BTW, there should be a torsion spring for keeping it on the trigger and making it ride correctly in the frame. Look at item # 71 on this exploded diagram of a 27-3 at Numrich. That part is the same on a 27-3 as the 27-2.