The licensing key you need if you want to add Vienna Instruments to your sound library.
In order to run any of Vienna Instruments' virtual libraries, from single-themed collections like the Bosendorfer Klavierabrik piano or Chamber Strings, to the Super Package which bundles eighteen different instrument libraries in one, you'll need to get the Vienna Key USB dongle. Developed by Syncrosoft, this protection device allows you to run whatever title you purchase on one computer. If you have multiple collections, and want to run different instruments on separate computers, you'll need more than one Vienna key. You can move licensing information between USB keys, but you can't have the same Collection on two keys at the same time. The Vienna Key also gives you 180 "starts" if you want to demo a product first, which includes instantiating an instrument, loading a collection or instrument, and auditioning them.