WOW!!!
I got my $50 unit in two days, and it's impressive. It was easy to install the software on my 8.1 laptop. I had to tell it a few times to go ahead and open the site and the software. It's a snap to use. I got the flexible 40" shaft version and recommend it.
I'm not sure I am happy I got it, however. Every bore I checked had me shaking. How could anything so rough and messed up shoot so straight!