A tool is provided for use with a bone anchor, wherein the bone anchor has an anchoring section and a receiving portion for receiving a rod to be connected to the anchoring section and a locking element, the tool comprising a tip portion for engaging the locking element a mechanism to apply torque to the tip portion comprising a drive shaft and a driven shaft coupled by a gear unit, where the drive shaft has a different axis than the driven shaft, and where the driven shaft comprises an engagement portion configured to connect the driven shaft to the gear unit and a counter-holding portion for engaging the receiving part, wherein the counter-holding portion is rotatable with respect to the tip portion.
