Epson T8581 Black Ink Cartridge (OEM code C13T858100) is an extra high-capacity ink solution designed for high-volume, professional printing environments.
 
Product Code    (OEM)C13T858100.
Epson Series       T8581
Estimated Page Yield    Up to 50,000 pages (based on ISO/IEC standards).
Primary Compatibility   Epson WorkForce Enterprise WF-C20590 (and related models in that series).