That information doesn't tell you much, but
mount | grep LexarMedia
shows the device file (it's the file that resides under /dev/ that the above command's result shows among other information). Command 'mount' without options shows all mounted devices (you'll need to have the stick plugged in and mounted while you do the above) and grep picks up the line that talks about your stick.
When starting to do the dd thing, umount the device; don't eject it, it has to be present on the system, but umount it so that the filesystem is not in use:
Another way is to command
right after plugging the device in; there's information about it.
EDIT: if you go on with 'sda1' and your device was called something else, like 'sda4', it doesn't harm unless there actually is a connected device that is 'sda1'. If the device is not present, you'll simply get an error. However if you had two usb sticks for example, or had a sata harddisk, then it would possibly produce an unwanted result. If you don't have sata harddisks and you only have that one usb stick plugged in, it's very probably /dev/sda1, but if there are other USB or SATA devices connected, it might not.
About these device namings:
sda = primary usb or sata disk
sdb = secondary usb or sata disk
hda = primary ide harddisk
hdb = secondary ide harddisk
sda1 = first partition of the primary usb/sata disk
hdb3 = third partition of the secondary ide harddisk