It took me awhile to understand that one too . Parallax refers to the point of impact in relation to the scope . Since the scope sits higher than the bore you need a point where your reticle and bore intersect downrange . As I gather it , most scopes are parallax adjusted to 200 yards right out of the factory . For ranges above 200 yards you' d need a scope with a parallax adjuster to compensate or your point of impact may shift , especially at high mag . I don' t know of any scopes that are truly " parallax free" . The manufacturer may have meant parallax free within common shooting ranges .