Hoya HMC 72mm UV (0) filter
Carefully used, without flaws, good conditions
this is the high quality UV "0" filter, not cheaper "N" or "C" versions
suitable for all 72mm threads like:
Sigma 18-35 1,8
Nikon Nikkor 135 2,8 DC
Nikon Nikkor 18-200
nikon Nikkor 28 PC
etc