This developer unit is compatible with IRC3320L, IRC3320i, IRC3325i, IRC3330i, IRC3520i, IRC3525i, IRC3530i, C3520i, IRC3025, and IRC3320 copiers.It corresponds to OEM part numbers NPG-67, GPR-53, and C-EXV49.The set includes four developer units.Each unit is designed for use with black toner in commercial and office printing applications.