The rollerball refill fits into the FriXion Ball 0.7 (2260) and the FriXion Clicker 0.7 (2270) and is equipped with the thermosensitive FriXion ink. This ensures that the ink can be erased using heat and then comes back thanks to sufficient cold. The mine is equipped with a pressure-resistant, conical stainless steel tip. Ball diameter is 0.7 mm (M), while the line width is approximately 0.4 mm. Note: The FriXion ink is not document-proof.