It depends on what type of USB drive (hardware) you mount. If you're uncomfortable looking through the
dmesg log you can use the tool
hwinfo to find this out.
$ sudo hwinfo --cdrom|grep "Device File"
Device File: /dev/sr0 (/dev/sg1)
Device Files: /dev/sr0, /dev/block/11:0, /dev/scd0, /dev/disk/by-path/pci-0000:00:1f.2-scsi-1:0:0:0, /dev/cdrom, /dev/cdrw, /dev/dvd, /dev/dvdrw
The "Device File" is the device you're looking for. If you want to see all the manufacturer info about the CD/DVD drive you can run that same command without the
$ sudo hwinfo --cdrom
However, I usually do not include any
-type when mounting most CD/DVDs. If you have to provide a type it's typically
-t iso9660 for CDROMs and
-t udf for DVDs.