If your Cartier pen twists or clicks at the top to deploy the point, it's a ballpoint. Check out the Ballpoint Refills for Cartier window below. Carefully compare your old refill to these options.
If your pen has a removable cap and isn't a fountain pen, then you see if we have an option that matches your old refill by clicking on the Rollerball Refills for Cartier window below.
If you don't see a match, please feel free to call us at 800.766.7367 and we will try and help identify your refill and resolve your dilemma.