The Kratonite plateskirt is a Tier 4 plateskirt that can be found within Daemonheim. It can obtained as a drop from many monsters, or smithed using 3 Kratonite bars with 37 Smithing granting 121.5 experience. It requires 30 Defence to equip.
This item can occasionally be found as starting equipment at complexity 1-4, if a player has less than level 60 Defence.