Cross Screw-in Converter for Cross Fountain Pens (8756), fits Century II, ATX, Peerless 125, Botanica, Bailey, Beverly, Apogee, and Sauvage fountain pens Compatible with the following fountain pens: Century II, ATX, Peerless 125, Botanica, Bailey, Beverly, Apogee, and Sauvage Enables the use of bottled ink in place of fountain pen ink cartridges For use with authentic Cross Bottled Ink