This Upper Fuser Roller is designed to be compatible with FS 2100D, 2100DN, M3040dn, M3040idn, M3540dn, M3540idn, M3040, M3540, and FS2100 printers. It is an easy install replacement part. The Upper Fuser Roller is responsible Compatible With applying heat and pressure to the paper during the printing process, ensuring proper fusing of the toner onto the paper.