The SIX Okidata Microline 182/184/186/320/321/390/391 Compatible Ribbons 52102001 are black ink ribbons designed for use with printers from the brand Associated Supply and compatible with Oki printers. These ribbons are of the seamless type and are suitable for models ML 320, ML182, ML321, ML 390, and ML 391. They provide a reliable and consistent printing experience for these specific printer models.