EM4100/TK4100 is not rewritable or programmable ，you can only read it ， If you want copy/dupulicate an EM4100/TK4100 card，This item is what you are looking for!it can copy/duplicate/program an EM4100 to a T5577 Card.It has nothing to do with HID!!!Specification:125khz RFID reader/writer with USB interfce.It can support Write/Copy EM4305，ATAT5577， T5557， T5567， or compatible cards/tags.It can support Read EM 4001，EM4200 or compatible cards/tags.Could Read and Write and copy/duplicate ID cards and re-useApplication:Widely used in entrance guard， consumption， hotel lock， water meter， electricity meter and gas meter and a series of IC card management application system.Product parameter:Chip type: ATA5577Storage capacity: 363bitsEndurance: 100，000Operating frequency: 125KHZData Retention: 10 yearsCommunication speed: 9600bondsRead/write Distance:0-10cmPackaging materials: ABSDimension:105X70X12mmOperating Temperature: -20 degree ~ 55 degreeWeight:90gSupport System:Windows 2000/ WIN7/WIN8/NT /ME /VistaSupport write/copy cards/tags type:EM4305， ATAT5577， T5557， T5567，or compatible cards/tagsSupport Read: EM 4001，EM4200 or compatible cards/tags.You'll Receive:1 x USB 125Khz RFID EM4305 T5567 Card Reader/Writer Copier/Writer programmer burner5 x Rewritable tagHow to use:Read card:Read card does not need to click on the choice of the card type，put the card， click "read" buttonFor example: EM4100 card number is 0006703889 102��19217�� 012 is the version number or customer number， 0006703889 is the 10 number， 10219217number is 8.Write card:1. Choose the card type， T5577 or EM43052. "+1": write a card， the card number will automatically add 13. "protection": otherequipmentcan notchange thecard number4. Selected card type， put the card ，put the card， click "write" button