PREMIUM QULAITY OF OKI GENUINE BLACK RIBBON CARTRIDGES YIELDING APPROX 3M CHARACTERS. COMPATIBLE PRINTERS (IF ANY): OKI MICROLINE 172,OKI MICROLINE 182,OKI MICROLINE 183,OKI MICROLINE 184 TURBO,OKI MICROLINE 192,OKI MICROLINE 193,OKI MICROLINE 320E,OKI MICROLINE 320 TURBO,OKI MICROLINE 321E,OKI MICROLINE 321 TURBO,OKI OKI MICROLINE 280ECO,OKI OKI MICROLINE 280 ECO