17500 battery

What could this be used in? I I have a bunch of these.

Two 17500 batteries can fit into unbored surefire M3, C3 and 9P hosts.

I think you can also use them inside 3xAAA flashlights. Lenght is the same, but diameter is less.
Voltage is OK.
Because it has less resistance, output may be more than 3xAAA.

If you put 2 x 17500 in a C3, am I right in saying that the result would be less bright than 3 x cr123a or rcr123a due to the reduction in voltage?