# How to see an RFID code on the Employee key? Every Hideez Key comes with RFID module and a unique code that has already been put in Em-Marine standard. It can be used as [key for physical doors](/hideez-key-enterprise-edition/key-for-physical-doors.md) . You must register the RFID code on the key.\ Please see the video how you can replace existing code on Hideez Key. {% embed url="" %} If you can use existing code and write it to other systems, for example your Access Control System, you need to know it. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://enterprise.hideez.com/hideez-enterprise-server/hardware-vaults/how-to-add-an-rfid-code-to-the-employee-key.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.