It requires a Defence level of 78 to wear and lasts for 1 hour of combat. After the time is up, the plateskirt will vanish.
A corrupt version also exists, which requires only 20 Defence and lasts only for 15 minutes of wearing (degrades even while not in combat).
Due to the Evolution of Combat update, this plateskirt now has stats that are equivalent to those of the statius's platelegs. The Statius's and Vesta's equipment sets are now essentially just melee style tanking gear. In fact this plateskirt is now only very marginally weaker than Torva platelegs.
Contrary to popular belief, this item does not degrade while using non-combat magic.