Y.K. Optical
Kobalux was the brand name of two wide angle lenses, made by a small Japanese company called YK of Yokohama, and available in Leica screw mount and Leica M mount. These lenses were also available under other names, such as Avenon, Komura, Pasoptik, Bower and Adorama.
There was a Kobalux Wide 28/3.5 and a Kobalux Super Wide 21/2.8, both in chrome or black finish. Cameraquest tells us that the 21/2.8 existed in at least three variants. The two lenses were sold together with an external finder.
Production stopped around 2002.