I need to get 5V 3A from a 6-12V input without a heat sink or fan.

I've got a lead on something...

I was looking at thus UBEC:

And one of the people that bought it had one of the leads come off and took it apart, and someone else recognized it as a KIS3R33S module. I'm not sure what that is yet, but apparently they're all over ebay.

And this is the chip used in them: