I normally wear a 8-8.5 narrow but these 8.5 mediums strangled my feet.  Had to return them.  New Balance needs to fix their sizing inconsistency. I order 8.5 for the WT20GP and they fit fine.  Another model, WT10GP in 8.5 was too big.  Please fix the sizing.  I'm sure your suppliers would appreciate it too, so they don't have to deal with all the unnecessary returns and associated costs.