You can have it installed on 5 products at once. Ideally you need to deactivate it on your old machine before moving to a new one. Not too long ago you could only deactivate the licence from the machine it was activated on, so if you forgot to deactivate a licence before you changed or sold a machine you would need to raise a service call with Arturia to unregister your machine. This has now been changed, you can now manage all your devices via your online account.