About This Pen: This Montblanc Meisterstuck Le Grand Diamond M23873 (106126) Pen has a rollerball writing system. It features a black precious resin barrel, complemented by a cap that is also made of black precious resin decorated with a Montblanc diamond in cap-top. Both clip and fittings are platinum-plated. The three platinum-plated rings on the cap is embossed with the Montblanc brand name.