This allows you to insert a AA size battery and use that battery in places that require a C size battery. I like to keep lithium AA's in my flashlights, because the alkaline batteries freeze and leak in the winter in Ohio. I had one flashlight that takes C cells. I downloaded a few of the other adapter available and I didn't like how they fit. So I designed my own. My design uses slightly less plastic then the others and does not require any supports.
The author hasn't provided the model origin yet.