Paralax Adjustment...

Generically thought of as a "focus" for certain yardages.

Paralax hits you hardest with variable power scopes and a quick way to test if a scope is paralax free is to look through it at a targetand then move your head just a little side to side, andup and down. If thecrosshairs move on the target more than just a little bitfrom you moving your head that way then your scope is not paralax free.

The Adjustable Objective is supposed to compensate for that in a variable power scope...

Use it as intended and set it on the yardage that your target is at...........