The Mighty Mouse 10440 lithium battery is about the size of a standard AAA but it is 3.7 volts instead of 1.5.  Many of the premium 1xAAA flashlights can take a 10440 battery including the Tank007 TK703 and certain manufacturer's revisions of the Tank007 TK701.

This battery needs a lithium recharger but the added voltage can really make some premium AAA flashlights blaze.

Note: 
This lithium ion cell has no protection circuit.  To date, there is no protected 10440 on the market.  One company claims to have one but the cell is considerably longer, so even if the cell is indeed protected, it is technically not a 10440.

This 10440 lithium ion cell should either be used in a device that has built-in overdischarge protection or used with caution in one that does not.  If you use this cell in a flashlight that lacks discharge protection, turn it off the moment you notice a distinct diminishing of light or if the light flickers.  This should keep you from overdischarging the cell. 

Only charge this cell in a charger that has built-in overcharge protection.