This Y.K. Optical six elements in four groups Kobalux Wide 28/3.5, also sold as Avenon, Pasoptik, Bower, Adorama is one of the most compact 28mm wide-angle lens for rangefinder cameras, featuring excellent optical performance, sharpness, tonal character and minimal distortion across the entire image area.
Originally made in 1981 in chrome with distinctive round focusing tab and a six-blade diaphragm and minimal focus to 1 meter. The second generation, or "M-series", was sold in black with a silver rim. It has a crescent-shaped focusing tab, an eight-blade diaphragm, grip tabs on the aperture ring and minimal focus to 0.75 meter.