If your S.T. Dupont pen twists at the top to deploy the point, it's a ballpoint. Check out the Ballpoint Refills for S.T. Dupont window below. Dupont's own refill is shown, as well as option from Monteverde that contains liquid ink.
We also carry the supplies you need to keep your S.T. Dupont multi-pen running. These include liquid ink mini ballpoint refills from Monteverde and pencil lead in .5mm and .7mm diameters.
If your pen has a removable cap and isn't a fountain pen, it's a rollerball! We offer S.T. Dupont original rollerball refills or a popular rollerball alternative from Monteverde. S.T. Dupont even offers a jumbo refill that contains oil-based ballpoint ink. Click on the Rollerball refills for S.T. Dupont window below to view your options.