This Teng Tools 10 piece combination spanner set consists of spanners which have the same dimension at both ends. One end has an open head, and the other has a 12-point ring head, which is set at a 15 angle to increase ease of access to the fastening. The spanners are manufactured from chrome vanadium steel for strength and durability and have a satin finish and polished heads. Manufactured to DIN 3113A standards. Supplied in a handy plastic holder, which is ideal for easy transportation, mounting to a wall or fixing on a workbench panel. The TEN6510A 10 piece set contains the following spanner sizes 8mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm and 19mm.