Rokinon mc 1:2.8 f=135 camera lens FOR KONICA Mount clear, clean, fungus free glass but focus ring slips.  The lens does function but slips! I'm sure it could be tightened by someone with the inclination! If tightened it would be a 39.95 lens condition wise! A good buy if you can deal with the slip!  Also, it doesn't do it all the time.