For what it was designed for, it is what it says. "It helps get you sighted in". It doesn't make an AR a tack driver at 1K. But at 50 yards it got me 2" off the "X" ring. Sighted it there then moved back to 100 yards. It was close enough from 50 yards that 100 didn't need it to get on paper. It was already very close. It just needed a little to fine tune it. All in all a good idea if you have troubles getting on paper. Be sure your crown is cleaned and doesn't have carbon buildup on the face of the muzzle. If your rifle has a flash hider you may have to remove it. But try it first with it on first. Just remember to remove it before pulling the trigger. Good luck.
Pros: simple to use, gets you on paper the first shot
Cons: not exact, but it isn't advertised as such.
This review was written in the old system and had content requirements that are different than reviews written today.