Name: Armor Upgrade Mk4 Classification: Armor Upgrade Time to Research: 3:00 Prerequisites: Armor Upgrade Mk3 Leads to: Nothing Gameplay: +25 to max armor, -4 to max speed, +1 to armor charger rate The Mk4 armor enhancement is revolutionary in the development of personal defense. When equipped with Mk4 armor technology, security guards from your company will be nearly unstoppable by anything short of a tank.