This is a Yashica made Yashica ML 135mm f2.8. It feels like a 135mm Sonnar. Focus dampening is smooth yet strong. Aperture clicks quietly but positively. It has a built in hood. Focus throw is quite long. Minimum focus distance is approximately 4 feet.

I've only had a few minutes with it but it appears to be quite good. F2.8 is a tad soft but it tightens right up by f5.6. It is quite usable at f2.8. F5.6 it is sharp all the way to the corners. Fringing can be seen at 100% but it's minimal. Bokeh is quite pleasing. Contrast is excellent. Color rendition is very accurate. Black and white tonality is a tad flat but quite usable. This is one of the best 135mm's I've ever used.