Works just fine
I've sighted in 2 guns with this, a 10/22 and an ar15. took me all of about 30 seconds each. went to the range and both were within 3" at 50yds. three rounds later i had both guns hitting true. this is not what i would consider "professional equipment" but is very adequate for doing the job. others have said they had to make modifications to get it to work. i have no idea why, i removed it from the package, stuck the correct end on it for my bore size, stuck it in the gun, turned it on sighted the scope in down my hallway (about 30ft) and was done. the price is so reasonable ($30) that i can't believe how well it actually worked. i half expected to end up using it to play with the cat but it is now safely sitting in my gun cabinet (batteries removed) waiting for it's next job. i would recommend this item.