D&D 5th: Demon Tower of Madness
+1 Cloak of Protection
The various forms of this marvelous device all appear to be normal garments made of cloth or leather. However, each plus of a cloak of protection betters Armor Class by one and adds one to saving throw die rolls. Thus, a cloak +1 would increase Armor Class 10 (no armor) to Armor Class 11, and give a +1 bonus to saving throw rolls.