Open heel general purpose trek fins made from lightweight, durable materials in a compact size; Short, vented blade features molding and side ribs that direct water backward to increase power while minimizing fatigue; Comfortable, ample foot pocket with drainage vents and slot can accommodate larger booties; Adjustable straps with quick-release buckles and thumb loops for easy donning and doffing. Available sizes: small (4-7), medium (7-10), large (10-13).