How do I properly use this "Buck Toot"?

Hi there. I saw this and it seems useful, but before I buy it, I would like to understand more about how to use it. Thanks! Steve

7027 "BuckToot" LED Driver Module - COM-09642 - SparkFun Electronics?

Looks to me like you connect volts at one end and an LED at the other. The LED will receive 350mA current.

It seems expensive for what it is though. I guess it's because it's so small.

(350mA is usually for 1W LEDs...)

it says "does not require external current limiting resistors or additional heat sinking"

IT DOES NOT MEAN Your 1W led's don't need a heatsink

k thanks! Karma given! steve