A dongle can be bought in addition to each active (less than a year old) permanent vvvv beta license.
Using a dongle when deploying a vvvv beta project adds the following:
- The source code of your project is encrypted
- Allows you to limit the period of time the project can run
- Requires a dongle for each running instance, effectively allowing you to determine the number of copies your projects can run
Read all about how it works on the Protektor page.