Photo of a [[Montblanc]] [[Montblanc No. 4|No. 4]], showing the patented ({{Cite patent|FR|379615}}) cap needle that blocks the closure if the nib is not completely retracted. | Photo of a [[Montblanc]] [[Montblanc No. 4|No. 4]], showing the patented ({{Cite patent|FR|379615}}) cap needle that blocks the closure if the nib is not completely retracted. |