If it says small, then it's small. If it says large, then it's large. If it
doesn't say anything about size, then it's usually medium. Check and see
what races can equip it if you're in doubt. It usually good to get the
smallest size your race can equip because that armor will weigh less than the
same armor piece of a larger size, yet still provide the same armor class.

-Rydel of Bristlebane