This is the unlimited original dongle for inlab mcxl or mc inlab compact milling machines you will need this to mill unlimited on your newer software such as inlab 4x series of the software. It is already installed in the dongle as you can see in the picture i will also send you the envelope with the licence but please know that this is already installed on to the dongle shown. So it can not be used on another dongle. Just the one it alredy is included in the auction this licence only contains the unlimited dongle. For milling you will still need your software and licence