These thermal scopes also have different coloration modes that allow you to see the heat signatures based on the ease and comfort of your respective eye. My Rattler is very repeatable when taking it on and off of your rifle, holding inside of 1 inch of zero at 100 yards. https://infrared-telescope02356.bloggerswise.com/34500342/the-ultimate-guide-to-infrared-light-for-night-vision-scope