Sorry, exFAT is not supported by any Lumin device.
For small USB flash drives, consider using FAT32 for OS X.
Thank you again Peter. I really appreciate your help and information.
I need to copy files from an OS X formatted drive and want to use it on my Lumin U1 but OS X can't write to NTFS formatted drives.
Can the Lumin read USB drives formatted as ExFAT?