Abstract: A knob for a medical post valve, the post valve having a threaded bonnet with a diameter, and a valve stem, the valve stem having an external end shaped, generally, as a cylinder with two opposing flat sides, the knob comprising a hub having an elongated body with a diameter that is generally the same size as the bonnet diameter, the body having a first end, a second end, and an axial cavity, the first end having a medial slot extending in across the first end in a direction perpendicular to the cavity, an elongated handle, the handle sized to fit within the cavity, the handle movable between a first position and a second position, the handle first position being disposed within such cavity with the axis of the handle generally aligned with the axis of the body, and the handle second position being disposed within the slot with the axis of the handle extending perpendicular to the axis of the body.