OK Kult is, as far as I've heard - crap. It is basically an adaption of the original MAGIC RULES (not exactly a sourcebook, then) from the FIRST edition of Kult ever (1991, Swedish) - they have cut out various elements too, I'm told. Includes a short adventure.
If you want to see more on OK Kult (cover image, etc) and other Kult releases - go here: