This is the fourth tier chestplate in the DragonRealm mod. It is an upgraded version of the Hunter Dragon Chestplate.
This is the last tier of the DragonRealm chestplates and cannot be upgraded any further. You can repair it with Dragon Ingots in an anvil.
A debuff will be applied to you if you are holding this item without having first earned the Alpha Master achievement. The debuff is Mining Fatigue II and Slowness IV.