Just For Men Autostop is a new radically easy process. You comb directly into your hair with the precision applicator. No mixing is required. The comb can be used to target only the grey hair areas. The new “Auto Stop” technology shuts itself off after 10 minutes, where as regular hair colour gets darker the longer the product is left on the hair. Just For Men Autostop is the gentlest permanent hair colour available. It does not use Ammonia or Peroxide.