WIFI/BT Inspection borescope.

I bought a cheap < $20.00 borescope through Amazon,
The brand may be kkmoon
At least that is what the web site address begins with.
Works great, connects via Bluetooth to my phone, there is a dial to adjust the light intensity, even records short video clips.
The lense of the one that I have fits into a sparkplug hole, there are borescopes that have larger diameter lenses, probably gives a larger field of view but may not fit inside a sparkplug whole,.