There are two artists called Kooler. 1) An alias of Sebastian Mullaert (aka Ooze). Produces progressive house/trance, and has released one 12" and one full-length album, "Open".
2) A collaborative alias used by Pete Namlook and producer Robert Sattler, for jazzy, metropolitian environmental chill-out, with Sattler on saxaphone and trumpet.

Read more about Kooler on Last.fm.