12 piece Anti-Slip metric combination spanner set Sizes 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19mm Anti slip grip on the open end as well as the hip grip function where the spanner drives on the flank of the fastening rather than the corner Hole in the handle for securing the tool while working at height The design also provides grip on fastenings with worn or rounded corners. These two design features combine to provide a much better grip with less risk of damage to the fastening Supplied in a handy durable storage wallet with hanging holes Manufactured and designed in accordance with DIN3113A in high grade chrome vanadium steel. The ring head is offset 15 degrees to facilitate use even on flat surfaces. All ring heads are equipped with Teng Tools hip grip system, which means the contact surface grips on the flat surfaces of the nut or bolt head rather than on the corner. This system helps to prevent damage to nuts and bolts and makes it possible to grip nuts and bolts which already have damaged corners.