The 125 mm stopper for the Marker Kingpin is the replacement ski brake for Marker's pin touring binding, not a bottle accessory. Its defining behaviour is that it locks up automatically when the binding goes into walk mode and re arms the moment you switch back to ski mode.

• A ski brake, not a bottle stopper: stopper is Marker's term for the brake on a binding heel.
• Automatic lock in walk mode: the brake retracts itself when you switch to walk and deploys again on the way down, with nothing to remember at a transition.
• Kingpin specific: it fits the Kingpin touring binding and will not fit Marker's alpine Royal Family bindings.
• Covers 100 to 125 mm: one part spans that width band, with a separate 75 to 100 mm version for narrower skis.
• Low profile: the brake sits close to the ski rather than projecting far beyond the edge.
• A ski brake