The MaximumComponentLength property contains the maximum length of a filename component supported by the Win32 drive. A filename ...

The MaximumComponentLength property contains the maximum length of a filename component supported by the Win32 drive. A filename component is that portion of a filename between backslashes.  The value can be used to indicate that long names are supported by the specified file system. For example, for a FAT file system supporting long names, the function stores the value 255, rather than the previous 8.3 indicator. Long names can also be supported on systems that use the NTFS file system.
Example: 255