Hi @anaomar and thanks for your query. In order to use the Tobii 4C in conjunction with the Tobii Pro SDK, you are required to purchase a special
analytical use licence and a special unlock file.
You can read more about this @ https://developer.tobii.com/license-agreement/
To request a quote please get in touch with the Tobii licencing team @ https://developer.tobii.com/license-agreement/contact/
Please do let us know if we can provide any further information. Best Wishes.