Britool Combination Spanners (metric) are forged in chrome vanadium steel and have a high chrome finish. The ring spanner end has a 12-point OGV profile angled at 15, maximising the contact surface with the nut for a longer lifetime. The open end is angled at 15 from the handle axis. ISO691 - ISO 1711-1 - ISO 3318 - ISO 7738 - DIN 3313. This 18 piece retail pack contains the following sizes 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 and 24 mm. Supplied with a tool roll for easy storage.