Be Green Ink Compatible Replacement Black Toner Cartridge for Lexmark MS310dn MS312dn MS315dn MS410dn MS415dn MS510dn MS610dn 50F1H00 Black Toner (2 Pack 5,000 High Yield) Ink Cartridges (Aftermarket) - Newegg.com
Lexmark 50F1X00 Toner - Lexmark 501X Toner Black @$86.99