This borescope works good for me, connected to my Windows 10 laptop. The probe and mirror is only .20" in diameter, the semi rigid cable is 40" long, the LED lights are adjustable and can be turned off, since they do heat up the probe when on high.
The 45 degree mirror is attached by threads and can be screwed in or out to adjust the focus to fit the gun bore from.22 to .50 cal rifles. It should work on shotguns too
It comes in a black foam padded manila cardboard box that is 8 3/4" X 9" and 1 3/16" thick the 40" rigid cord and the connecting coil coil up nicely in the box. the cord will fit several sizes USB computer and smartphone connectors, The description on Amazon is right on, no surprises here.
You can also see these on Teslong's website. I ordered mine from the Teslong store on Amazon. It was direct shipped from Teslong.
It worked well to inspect the gas port on my .308 you can really see the condition of the rifling, and chambers.
I also used it to check the bore rifling and breech plug condition of my 40 year old CVA 32" .50 muzzleloader.
It was well worth the $50 to me since I do have Amazon Prime with the free shipping it came by USPS.