Shells will vary slightly in color.

For size, measure around your hand at the base of your hand, slightly cupped as if you were putting on a bangle - see last photo.

x small         7" 
small            7.5" 
medium      8" 
large            8.5"     $105
x large         9"         $105
xx large       9.5"      $108
xxx large     10"       $110