This tool is nothing more than a short fiber optic wire attached to a rubber hood, which goes on the end of a Maglite or equivalent. It completely gets rid of the problem of aiming a flashlight beam into a small hole. Just insert the end of the adapter and voila, the inside is lit up and you don’t have to contend with all the glare from the light hitting the edges of the hole. Comes in 7″ and 20″ versions.
It’s simple, inexpensive, and essential.