An armshield is a shield designed to integrate with the forearm of a warforged. If you’re a warforged, you can attach an armshield by attuning to it. An attached armshield cannot be disarmed or removed from you against your will, but while the shield is attached you cannot use that hand for other actions. You can spend one minute to end the attunement and remove the armshield. 

Notes: Bonus: Armor Class