Infernu

I'm working on a new E-11 blaster, like everyone, I started studying some pictures of blasters screen used. I was checking some reference pictures and watched a small flange on the m38 scope of some ANH stormtroopers and Sandtroopers. Maybe it's an old topic, but I would like to know if there is information about. Here some pictures. observe the red arrow that points to the ridge (I called CRESTA is Spanish )