I ordered this set and want to assemble 43 to 52mm Ring with 52-er polarizing filter on my Biogon. If re then dropped the Polarizer including adapter to the ground. Bin then the cause went to the fermentation: On the ring is 43mm TO 52mm. But he has measured it only 40,3mm! This is absolute junk. Now I know why the scrap was so cheap! I would love to give minus 5 points for the defective polarizing filter again minus 20 points. Unfortunately it does not work! My first disappointment on Amazon. Let merely the fingers of the stuff !!!