My original trigger broken after quite a bit of use, but the unit still works fine so I just took many measurements and made a duplicate. I suggest using a 3/16" drill bit (the post it sits on is 5mm and the drilled hole should be just over 4.7mm which creates a nice interference fit so it doesn't fall off) and drill out the hole to make it fit better. The hole in the stl is 4.7mm. You will need to use supports. I printed it on it's side and bottom and printing with the trigger facing up works the best.