??DO NOT WORK FOR PRINTERS PURCHASED AFTER March 1st, 2019??If You Purchased Your Printer AFTER March 1st, 2019, Please Check the Serial Number (S/N) before order. This is why this Original Ink at affordable Price.??Check Serial Number to see if your printer Works??The key is the last 6-digit of your printer. Those Original Ink Cartridges Work for Printers with Smaller Serial number as below: ?? WF-4720: <159986, e.g. X2TS 159000 works, as 159000<159986; ?? WF-4730: <181123, e.g. X3G6 181000 works, as 181000<181123; ?? WF-4734: <163142, e.g. X3Y9 163000 works, as 163000<163142; ?? WF-4740: <090768, e.g. X2TY 090000 Work, as 090000<090768.???WORK FOR?WF 4730, WF 4720, WF 4734, WF 4740, EC 4020, EC 4030, EC 4040 Printers PURCHASED BEFORE March 1st, 2019 FOR SURE.???POWERED BY ORIGINAL INK?Better Than ANY Other Refilled or Re-Manufactured Third Party Ink, Our Cartridges Are Repackaged From Unused ORIGINAL Brand 802 Ink Cartridges.?HOW TO DISTINGUISH BETWEEN ORIGINAL BRAND 802 INK AND REFILLED OR REMANUFACTURED THIRD PARTY INK?The Point is the Refilling hole. There is A Simple Method: Tearing Off The Covered Labels Of The Cartridges To Check If There Is Any Hole On The Cartridges. If Yes, The Cartridge Was Refilled With Third Party Ink.?NOZZLE CLOGS?There Is Huge Gap Between Original Ink And Third-Party Ink. You May Feel The Ink Is Just Water With Some Dye. Actually, It Is Not That Simple As You Feel. Micro-Electro-Mechanical System technology is used to Make the Print Head and its nozzles. And the Size Of the Nozzle is Only 10 Microns (0.0003 inch). In Order To Avoid Clog The Nozzles, Ink Itself Should Have Nano Technology Involved. This is Why Third-Party Ink is Easy to Clog Your Printer.