THEY ARE PRODUCED BY A DIFFERENT SUPPLIER THAN THE 'NON ECO' SERIES. 12 MONTH WARRANTY! HP LASERJET 4100, 4100N, 4100TN, 4100TN, 4100DTN, 4100MFC Compatible Printers. COMPATIBLE BLACK C8061X TONER ECO SERIES FOR HP Laser Jet 4100XX CAPACITY 10,000 Pages.
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