Replaces the Following Manufacturer Numbers: OKI 42377801. Compatible with the Following Printer Models: OKI Microline 420, OKI Microline 420N, OKI Microline 421, OKI Microline 421N, OKI Microline 490, OKI Microline 490N, OKI Microline 491, OKI Microline 491N.