bmatcuk

# First, we need to find our device. BEFORE inserting your USB drive, run the
# following:
diskutil list

# This will output a bunch of info about all of the disk drives connected to
# your Mac. Each entry will have a header in the form "/dev/diskX", where X is
# some number starting at 0. Now, insert your USB drive and run the command
# again. You should see a new entry. Make note of the name (ie, /dev/diskX).
diskutil list