Agamon
Adventurer
Depending on the magic in the world, it may very well be called +2 Armor. I wrote this up several years ago and will cut paste:
Well, yes, the level of power would be distinguishable, otherwise why would a PC trade in a +1 sword for a +2 sword? I'm just saying, as you admitted in your post, that literally calling it a "+2 magic item" in game would be an unusual game.