Shield, +1, +2, or +3

Armor (shield), uncommon (+1) rare (+2) or very rare (+3)
While holding this shield, you have a bonus to AC determined by the shield's rarity. This bonus is in addition to the shield's normal bonus to AC.
Dungeon Master´s Guide (SRD)
  1. DnD 5e Magic Items › Shield, +1, +2, or +3