Source: Explorer's Guide to Wildemount

Armor (shield), rare (requires attunement)

While holding this iron tower shield, you gain a +1 bonus to AC. This bonus is in addition to the shield's normal bonus to AC.

Additionally, the shield has 3 charges, and it regains 1d3 expended charges daily at dawn. If you are holding the shield and push a creature within your reach at least 5 feet away, you can expend 1 charge to push that creature an additional 10 feet, knock it prone, or both.