Surefire UB3T build differences

I just purchased a third UB3T Invictus from the Botach Surefire sale and the beam is very different from my other one. My original one is a Bxx8xx serial and the new one is a Bx28xx serial. The 800 series has an almost square beam profile and has a very cool tint and the 2800 series has a much more rounded profile and a warmer tint.
Now the interesting part is that both TIRs look exactly the same, I've seen some M3LTs and UBRs where you can see the emitter in the center, but this is not the case here. Anyone else noticed this?
Beamshots will be upcoming.

I think your new UB3T has been sitting around for a while because the serial number is quite low. Your old light might have the MC-E, which would explain the square beam pattern.

More info here:http://www.candlepowerforums.com/vb...ost-your-Surefire-UB3T-serial-number-registry

There were two changes, LED upgrade (MC-E to XM-L) and optic revision, and it sounds like he has an XM-L without the new optic. Either his new UB3T was an older model caught between the two updates, or the optic has been changed again.

Cool thanks for the replies, I didn't know they changed the LED.