5mm Stainless Steel Stabiliser lock. Locks the stabiliser leg in the down position. This stops the leg from being lifted. The caravan is unable to be towed with the stabiliser leg locked down. The only way to lift the leg is to remove the lock. The leg cannot be wound up or rotated.
To fit the lock it does require a 10mm hole to be drilled into the front of the stabiliser to line up with an existing hole in the cam.