Schlumpf Box Spanner

From the Schlumpf website: "To tighten the lockring, please use the box spanner of our "profi" tool set. It's the easiest way to tighten it with the recommended torque of 100-110 lb ft, which is required to hold the gear housing against the reaction torque. The spanner is guided by the spindle, and provides a safe tightening without the danger of slipping. This box spanner can be combined with a 1/2" torque wrench."