It's simple, no more guessing. I just put this on so I have only been using it a couple days. I wanted to make sure I had the most accurate sight in possible so it took a couple days, but it could easily be done in an hour or two. 50 yards was the farthest I could shoot so I marked 20 and 50 then matched it up to the tapes and found the one that matched. So far so good, spent time yesterday shooting at random distances in the yard. From 20 - 50 so far I have not found a single distance it's not spot-on down to the exact yardage. Just like using a slider on your bow, there will be times where you do not get to adjust, but I kept my original crossbow scope on there for those times.