Hauser 707 SF refills are standard-size ceramic roller ball cartridges and fit any pen made to the common Schmidt 888 refill standard. Brands whose rollerball pens accept these refills include Faber Castell, ACME, Monteverde and Visconti.
Pen brands that are not compatible with Hauser refills include Cross, Mont Blanc, Parker and Pelikan. These brands use proprietary refill cartridges with different dimensions; Hauser refills do not fit properly inside the bodies of these pens.
Schmidt 888-compatible refills are sold under numerous brands besides Schmidt and Hauser. Caran d'Ache, Monteverde, Yafa and Visconti are brands that produce their own branded refills compatible with the Hauser 707 SF. This refill standard is used in capped rollerball pens; since it is not designed to guard against the ink drying out, it is not used in most capless and retractable rollerball pens.
Rollerball pens differ from ballpoint pens in their ink composition. They use water-based ink, while ballpoint pens use oil-based ink that is less prone to drying out. This water-based ink is why regular rollerball refills are not used in capless pens. Schmidt makes a standard refill for capless pens with a different ink formulation, but this refill is sized differently and is not compatible with pens that take Hauser 707 SF refills.