Heavy Shield (5e Equipment)
From D&D Wiki
This massive shield resembles a portable wall. Its sheer size and weight make it abnormally difficult to use.
Proficiency. To wield a heavy shield proficiently, you must have proficiency both with shields and with heavy armor.
Special. While you are wielding a heavy shield with which you are proficient, when you take the Dodge action you gain an additional benefit. You gain half cover until the start of your next turn.you can spend a reaction to give someone within 5ft half cover.