Bob, follow the instructions, from the Calibre FAQ's/use manual, and you will get the exact info for your device.
In addition to the Connect to Folder function found under the Connect/Share button, calibre provides a User Defined device plugin that can be used to connect to any USB device that shows up as a disk drive in your operating system. Note: on windows, the device must have a drive letter for calibre to use it. See the device plugin Preferences -> Plugins -> Device Plugins -> User Defined and Preferences -> Miscellaneous -> Get information to setup the user defined device for more information. Note that if you are using the user defined plugin for a device normally detected by a builtin calibre plugin, you must disable the builtin plugin first, so that your user defined plugin is used instead.