Scrap Plate, perhaps from a dead adventurer, certainly rusted and dented.  On a critical hit against the armor it is unusable until repaired.

Plate consists of shaped, interlocking metal plates to cover the entire body. A suit of plate includes gauntlets, heavy leather boots, a visored helmet, and thick layers of padding underneath the armor. Buckles and straps distribute the weight over the body.

Notes: Bonus: Armor Class, Str. 15 Required, Stealth Disadvantage