The RFID Tag allows the Digilab 3D45 printer to identify what type of filament is loaded into it. With this information, the 3D45 will set the correct temperatures and print speed to ensure your selected model prints optimally. It will even do this if the original print file was sliced for a different material. The RFID tag also allows the 3D45 to keep track of the amount of filament remaining on the spool so it can warn you if there is not enough to complete a print.