Magic Item Of Automatic Concentration (5e Equipment)
From D&D Wiki
These magic items were created by nostalgic spellcasters, who have seen better days, when there was no such thing as "Concentration" - and tried to bring them back. Such items can be made in shape of pretty much anything - from books, to trinkets, to jewelry.
While you are using Magic Item Of Automatic Concentration, it concentrates on your spells instead of you. You can benefit from unlimited number of Magic Items Of Automatic Concentration. Additionally, while you're using Magic Item Of Automatic Concentration, you will successfully maintain concentration, and won't loose concentration no matter what - even when you're getting hit by certain environmental phenomena, damaged, incapacitated, or killed. Each Magic Item Of Automatic Concentration can only concentrate at one spell.
Rarity: Legendary
Weight: Negligible.