This product is a replacement
laser pointer tail cap for the Mini-Mag® AA flashlight. Just replace the existing
tail cap and have a laser pointer that never needs
batteries of its own. If you work anywhere with a high ceiling or a need to point to
anything, this is a must have tool. Once you start using this laser pointer
attachment, the first words from others is predominately "NEAT" or
"COOL". Just like everything else, necessity is the mother of
invention. When I was trying to point to some electrical conduit where I work, the
ceiling was at 30 feet. Whipped out the Mini-Mag® and tried to show an electrician
which one went to a certain machine. Neither he or I could see the spot from the
flashlight. I did plan ahead. Out came the keychain with the laser
pointer. "That's the one". In went the keys back in the
pocket. I repeated this operation about 6 different times until I had a flashlight
in one hand and just left my keys in another. It finally hit me. It just might
work.
A couple of days later, my keychain laser pointer was in pieces and my flashlight tail
cap had a hole through it. Some quick machining and I had a laser pointer on the
back of my flashlight.
By rotating the tail cap outward with the
flashlight on, a switch is activated that turns off the main lamp and enabled the laser
pointer. A couple of weeks later, I was making them for others. I changed a
few dimensions and the size of it was small enough to be used with other accessories
already on the market. (e.g. pouches and specialty holders) 
The very best part of this was that I never have to find a "hearing aid"
style battery again (~$1.00 each) for the keychain laser pointer I once had.
AA batteries are cheap.
Since I never go anywhere without my flashlight, I can leave my keys in my pocket, and
still point to the conduit in the ceiling.
There were some skeptics out there. "Who would use that?" (He's a
pipefitter) 3 days later, he came back and said "That would of been handy if I
had it yesterday" He got 2. One to carry with him and, he said, one to
disassemble. (I wouldn't tell him how it shut off the main lamp when the laser is turned
on.) Since then he's been picking some up for his co-workers.
