After gaining momentum over the past 2 years, Crocs expands its Echo Collection with the launch of the Echo Wave. Arriving in a 'Black Sand' shade, the digitally-inspired sculpting and texture conjures a future-ready look that seamlessly marries the upper with the sole unit, which houses the irresistibly comfy LiteRide footbed. This footwear features a synthetic upper and sole. The model number for this product is 210521-0LD.