To protect your investment longer after the warranty has expired, use only genuine Oki ribbons. Why take chances? Use the Oki 42377801 ML400 Series Self Inking Ribbon Cartridge that was designed by the same engineers who designed your printer. It's specifically manufactured to eliminate binding and wear on the ribbon drive mechanism.
Oki 42377801 Product Features
Black Ribbon, self inking cartridge for ML420/421 and ML490/ML491 24-pin printers.
Average 4 million character life.
Material: Nylon fabric, cartridge type, re-inking
Type: Black Ribbon
Microline 420 (Black)
Oki ML400 Series Self Inking Ribbon Cartridge Specifications
Part # 42377801
Comments about Okidata ML400 Series Self Inking Ribbon Cartridge:
We have tried the cheaper ribbons for our Okidata DM printers and found them lacking in many aspects. We will continue to purchase the Okidata ribbons for their long lasting, and excellent print characteristics. We will never go back to generic ribbons.
Bottom Line Yes, I would recommend this to a friend