Open and bi-hexagonal ends with 15° offset for greater access. Hardened and tempered, drop-forged chrome vanadium. High quality fully polished finish. Ultra-strong ballistic nylon storage roll. Includes sizes 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30 and 32mm.