Elastic velcro. A good thin sock in cordura 500 with good durability for exercise, running and hunting. Recommended for snow. Size guide: XXXS: Omkrets 100 mm Längd 70 mm XXS: O 120 mm L 90 mm XS: O, 140 mm, L 90 mm S: O 150 mm, L110 mm M: O 160 mm, L 125 mm L: O 180 mm, L 135 mm XL: O 220 mm mm, L 140 mm