It's 20X vise the 10X on Hawkeye. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

there is a newer version. It's wi-fi....to your phone......http://bulletin.accurateshooter.com/...opes-reviewed/

Screw the mirror in or out to focus.....
It's up to you on how clean you like your barrels.
I have a barrel with +5800 rnds. Krieger 1-14 6PPC.
After 10-15 shots it's easier to get the bulls. Is it me or the barrel? VFS.
The bullet is. Oh, it's jumping way out there on the lands....