Okidata OKI70012801 OKIDATA ML320/ML321 RS232C SERIAL INTRFACE. Compatable with these models: ML320
ML320TN
ML321
ML321TN
ML390
ML390T
ML391
ML391T
ML520
ML521
ML590
ML591
ML320TN
ML321
ML321TN
ML390
ML390T
ML391
ML391T
ML520
ML521
ML590
ML591