Clarks Unstructured Womens Un Loop Ave Slip-on Shoes - Black Leather New in Box An Unstructured® slip-on with stitching details for a handcrafted touch, Un Loop Ave has a uniquely lightweight sole, soft underfoot cushioning and a classic look. Its leather upper is hard wearing and durable, while a clever air circulation system keeps feet cool and fresh.. Expertly crafted for people on their feet all day. * Black leather upper * Unstructured® air circulation system keeps feet cool and fresh * Soft foam footbed * Breathable leather lining and sock * Lightweight EVA outsole absorbs shock * Heel height: 30mm