Rule no. 1. Never trust no descriptions, only your DMM and lux meter (if available) via ceiling bounce and direct beam readings.
The reason I ask is I purchased the 2 cell version and I'm thinking about getting an extension tube to make a 3 cell. I want to know for sure doing this won't burn out the driver since the voltage specs are different...
I have the 3-cell and I honestly can’t tell the difference when switching it from 2-cell to 3-cell. Perhaps with a lux meter you could but not with the naked eye and especially not without having both version side by side in direct comparison. Unless you need the extra runtime I wouldn’t bother buying the extension and risking burning out the driver.
I can't imagine why Trustfire would have two different drivers when it's just a matter of an extension tube being used but those who have tested both version claim there is definitely a draw difference between the two. One way that might give a clue about the driver is if your 2-cell version can be run from a single 18650. My 3-cell works in all modes even on a single 18650. It's an awesome light!
Johnny, I wouldn't chance burning out my 3T6 unless I was 100% sure they were both the same. BTW, mine does run on one cell. Ditto on the awesomeness. I love this light!