The sparkling gemstone on the clip, the small pen body that fits perfectly on a shirt pocket, these are the two factors that make the Boheme pen line considered one of Montblanc's most successful lines.
In particular, the Boheme Gold Plated Rouge version that you are seeing is the most ordered Boheme pen model thanks to the brilliant red color of the ruby combined with the Gold plating on the metal. The black plastic pen body of this pen also highlights the beauty of that red ruby. This is the ballpoint version and is currently available at the Genuine Pen store.
See price details here.