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 metric sizes 6 8 9 10 11 12 13 14 15 17 19 and 22mm af sizes 14 516 38 716 12 916 58 1116 34 1316 78 and 1