Entry Level Borescope
A ProVison small diameter 18" borescope and described in an article by "Real Guns.
Real Guns - Borescope!
I have also purchased the 45 degree mirror, extra bright bulb, magnetic tip and a rubber eye piece.
I have $167 in it and would like $125 to your door.
It works good enough to view the inside of the bore. It also comes in a nice hard case. The only reason I am selling it is my wife has bought be a Hawkeye borescope. (Lucky me)