Streamlight 1L-1AA, Compact II, and Protac 90 all run on both without changing anything, just drop the cell in and run. These will also run on a AAA in a pinch.
If you have the right adapters, just about any C or D cell light will run on both and many more cells:
I have one, it was on some kind of sale about 3 years ago
under $10 or i would not have bothered
may be a clone
the body is long enough for an AA, and big enough for a CR123
the spring takes up the slack, though an AA does rattle from side to side a bit
not sure if an AAA goes in or not, i Have AAAs so i have not tried
it even has a 2 level UI that is kind of different and cool
programmable, i.e. the user can program 3 different modes: High/Strobe/Low (factory default); High only; and Low/High, to program you have to tap the switch rapidly 9 times and hold it down the 10th time, keep holding the switch until the light turns off, then release the switch. L
Although I have too many flashlights anyway, my go-to emergency flashlights are:
1. 18650 flashlights that accept CR123’s. I also have a box of CR123’s in the closet and get new ones every 7 years or so.
2. Just about any long runtime rated AA or AAA light. Currently, for me it’s a toss up between two Coast Polysteel lights… I keep the smaller one in the car glove compartment with a Big Larry clone if I need to change a tire, etc.
Something else to consider, is that some 21700 lights come with a 2xCR123 adapter… and some will accept an 18650 in the adapter (not all).
As someone already mentioned, Streamlight currenltly offers a AA/CR123 light. I have an AA/CR123 Fenix headlamp in my emergency bag, but they stopped making it… or at least they stopped making the extension for the AA.
The Olight Transformer set.
The TC10 and TC15 are “vintage” Olight tube-lights. Normally in alu, sometimes SS.
Then came the SE Titanium Transformer Christmas set: 1 head, 1 tailcombo, 2 bodies.
An omnivore, you could feed it: AA, CR123A, 16340, and 14500.
No, it isn’t. You need to copy the whole link, included “search=hugsby” into the address line of your browser, and then delete the words (link is external). Well, that works for me!