The OKI 42377801 MicroLine 400 Series Ribbon Cartridge Lot of 4 is a set of genuine/original ribbon cartridges designed for OKI Data printers. Specifically for the OKI 400 Series, these black cartridges are compatible with dot matrix print technology, ensuring high-quality printed documents. This lot of 4 cartridges provides efficient and reliable printing supplies for your OKI printer, ensuring consistent and professional results with each use.