It is very easy to use and excellent plugin - SightMark Universal Green Laser Boresight Pro

I have had and used several laser boresighters and haven't cared much for any of them none of them were consistent or reliable.Then I read a write up on sightmark boresighters and decided to give this one a try.The first scope I boresighted with it put a nice small group of 3 shots 2moa up and 2.5 moa left,I adjusted the scope accordingly and the next group of 3 was dead on.I have used this on 17 set ups since then with much the same results.It uses a rare earth magnet so it even works on ss barrels.Its the best boresighter I have had yet and its a 'keeper'.

This product does work very well and will show up in daylight on a 50 yard target, but you must use a strong Riflescopes to see the green dot on 100 yard target.

It is easy to operate,

The device is solidly built and functions perfectly. My only complaint is that it should come with a case-- it is worth that protection!