Having uppers of which over 90 percent of the external surface area (including any accessories or reinforcements such as those mentioned in note 4(a) to this chapter) is rubber or plastics (except footwear having foxing or a foxing-like band applied or molded at the sole and overlapping the upper and except footwear designed to be worn over, or in lieu of, other footwear as a protection against water, oil, grease or chemicals or cold or inclement weather)