You can't determine whether a tag is read/write or read only just by looking at it; you need to have an RFID reader. If you didn't get it from us, there's no guarantee what sort of protocol and chipset is being used.
If that tag is from Phidgets, it is the 3902
, which is a read-only tag, so you wouldn't be able to change the data on the tag. With a 1024 and some read/write tags, you would be able to read the data from the first tag and copy it to others, though.