Magic Cuffs

Increases maximum mana by 20 and restores mana when damaged. 7 mana is the minimum amount of mana restored when damaged. Mana restored is based on the power of the attack, before factoring armor. An attack that deals 7 damage, while wearing 20 armor (So 10 points of damage negation) will restore 17 Mana (The base power of the attack). Drowning and Fire Blocks does not affect this.

With the Arcane modifier, it adds another 20 mana, totaling to 40 mana extra. Due to its effects, it can remain useful well into hardmode and is extremely valuable to magic players.