This teng tools 12 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 degree 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 din3113a standards the tentt1236 12 piece set contains the following spanner sizes8mm 9mm 10mm 11mm 1