What is USB Service on mobile router?

Zyxel_Bella

USB Service is a feature that allows you to share files stored on a USB memory stick or hard drive connected to your Zyxel device with users on your network.

Use the USB Service screen to set up file sharing through your Zyxel device. Once the USB storage device is connected, you need to enable file sharing and configure access permissions. Zyxel device LAN users can access the shared folder (or share) on the USB device. To access the USB Service screen, go to mobile router's local GUI: Network Setting > USB Service.