Zyxel provides these resources to help users document their deployments effectively. They can typically be accessed through the following channels: The Zyxel Download Library : The primary official source for firmware, datasheets, and Visio stencils
If you want, I can:
file and extract the contents to a memorable folder on your PC. Zyxel Community How to Install Stencils in Visio Zyxel Visio Stencils
For older or legacy devices, community-maintained collections on GitHub can be a lifesaver. How to Install and Use Zyxel provides these resources to help users document