This is interesting lens for macro(micro) usage. It consist of focusing tube and 4 elements system. One element includes F5.6 baffle that can be probably removed or replace by other value. I found great magnification if used reversed with M42 adapter (49mm to M42) that is included in this listing. Focusing on the lens is only fine tune focus/magnification effect. Focus point is basically around 2cm from the object. And the magnification is life size more then doubled on sensor.

There are few marks on coating, but lens will give 99% optimal performance.

*Lens has its own screw 37mm mount. Front filter diameter is 49mm. Lens oriented normally has only around 1cm flange focal distance.

Lens is displayed on beautiful black Praktica LLC, listed separately here: https://www.ebay.com/itm/326278780827