MTI TFC28 Compatible Color Toner Set (CMYK) for Toshiba E-Studio 2330c, 2830c, 3530c, 4520c 4 New MTI Compatible Toner Cartridges Yield: Color Cartridges - 24,000 standard pages High Yield: Black Cartridge - 29,000 standard pages OEM #s: TFC28 / TFC28K TFC28M TFC28C TFC28Y If you do not receive your product in an MTI-branded box, it is not a genuine MTI product. Let Amazon know.