I need to understand the 'Star subscription' system for Utrecht. Specifically, explain how the 'star' zones work and how they relate to travel coverage. Also, find out if there's a way to check the credit on an OV-chipkaart directly through the website.
Navigate to the 'Webshop' page. Set the 'Region' filter to 'Utrecht'. Set the 'Product type' filter to 'Star subscribtions'. Click on the 'Utrecht, 1 Star year 2025' product (or any Star subscription) to view its details, looking for information on how star zones work. If details are not sufficient, navigate back to the homepage or a relevant 'Travel info' or 'Customer service' page. Look for a link or section related to 'OV-chipkaart' or 'Credit checker'. Click on the 'Credit checker' link (id: 96) to find information on checking OV-chipkaart credit. Synthesize the information found on star zones and the OV-chipkaart credit check process.
Explain that 'Star subscriptions' in Utrecht are zone-based, with '1 star' covering a specific central zone and additional stars extending coverage to surrounding zones. State that the website offers a 'Credit checker' tool (or similar functionality) to check the balance on an OV-chipkaart. Provide the exact name of the link or section used to access the credit checker.