This Dymo device has 1 USB Port, that comes up as 2 USB devices in the system, (1) for the Label writer and (1) for Plastic Label Writer. This device is well supported by Dymo, use their website for the latest updates and software.
DYMO Connect for Desktop
File: DCDSetup1.4.3.131.exe
DYMO Connect for Desktop
File: DCDMac1.4.3.103.pkg
LabelWriter 300, 400, 450 Series Print Drivers
File: LabelWriterDrivers-x64.msi
f8f404765e62e52b9e9dad096ffd554bef1a657429e7f5f1ab0b266df30f7f04
LabelWriter 300, 400, 450 Series Print Drivers
File: LabelWriterDrivers-x86.msi
905e159a2dc5001a6a6c9d652ea5053ece535dddd179c230f8701ce880fa914b
LabelWriter Print Drivers
File: WinXPx64_BETA.EXE
6cf3b1df6d1c38e736472ce1085bc140ffa9b20c789862fac8d4032dac2d033a
DYMO LabelWriter User Guide
File: LabelWriter_UserGuide_en-US.pdf