these are neat glasses.  I don't really care about all of the folding business but I liked the metal finishings.  They are sufficiently tinted and the polarizing works.  I have a big head.  It was difficult for me to figure out the Persol sizing system.  Their website gives some insight.  I bought the size '54' and they are 14cm wide.  Size '56' is somewhat rare and is 14.5 cm wide.  These were slightly small in width on me but persol has some nice flexors built into the arms of the glasses that make them comfortable any ways.  I wear a 7" 5/8 hat for reference.
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