36 Pieces Oki, Okidata Microline ML 500, 520, 521, 590, 591, ML500, ML520, ML521, ML521, ML590, ML591, 52106001, 52107001 Compatible High Capacity Seamless Black Ribbons. Compatible with Nukote BM346, NK346, BM 346, NK 346 and Porelon 11513, 11514, 11914.