About This Pen: This Montblanc Solitaire Doue Signum M23366 Pen has a fountain pen writing system with piston converter (allows optional use of ink cartridges). It features a special design on its black precious resin barrel, complemented by a platinum-plated cap. Both clip and fittings are platinum-plated. The three platinum-plated rings on the cap is embossed with the Montblanc brand name. The nib is made out of 18K gold with rhodium-plated inlay and is hand-crafted by Montblanc. The following Nib Width are available: Identification No. Nib Widths08572 EF 08573 F 08574 M