Lexmark 56F1X00, 56F0XA0 Extra Hi-Yld Compatible Toner-Black. Compatible with 56F1X00, 56F0XA0 - Black. Fits Models: MS421dn, MS421dw, MS521dn, MS621dn, MS622de, MX421ade, MX521ade, MX521de, MX522adhe, MX622ade, MX622adhe - Extra High Yield