Monteverde USA ultra-smooth rollerball refills are designed for comfortable writing with your rollerball pen. This Monteverde USA refill set of two features a fine point in blue ink, and is a standard international size that fits many capped rollerball pens. The ink is non-drying and will last a year once the cap is off. Follow the instructions from the original manufacturer to replace your refill in your pen, and make sure to keep the internal spring in the same direction.