Upload & Sell: On
Ha ha, mine came with two installed and one spare. So yea, he might have received extras, and they're tucked away somewhere.
Same as mine except I installed all three but cut the first slot so I can put my 4mm thick CPL. I rotate the whole holder to get the desired CPL effect. Of course I can no longer use Grad ND filter but still use a regular (Non GRAD) ND to slow down shutter speed. My set-up is vignette free of but I'm limited to 2mm thick ND filter because 4mm thick would require 4 slots which has the vignette potential.
PS: This is based on 5d3+24-70m2