A back zipper is a slide fastener located at the rear of a garment or shoe. In footwear, a back zipper closure is mostly used in high top boots for women and is intended for esthetic purpose rather than functional.
About Evening Shoes:
Evening shoes are shoes marked by elegance. Evening shoes may be either very polished or extravagantly ornamented. Implicit in the name, evening shoes are most appropriate for evenings or events that call for formal attire.