The Ring of Runic Shielding is a bauble added by Thaumcraft 4. It provides 5 shield points against most sources of traumatic damage (e.g., mob attacks, falling) before full damage is inflicted on the player and their armor. It will not protect against damage from starvation or drowning. The runic shield will recharge over time by using and vis from carried wands.
Your research into protective magics have led you to discover Runic Shielding. This is not armor in the traditional sense, but a collection of charms, rings and similar protective baubles worn with your everyday clothes.
These devices create a barrier of magical energy that wards out most types of damage. The shielding has a pool of hit points from which damage is subtracted first, protecting the wearer from all harm. Once this pool is depleted the wearer starts taking damage as normal.
The pool replenishes over time and requires Terra and Aer vis to replenish its charge which it draws from carried wands.
The armor offers no protection from damage suffered due to drowning, starvation or similar environmental hazards.
Due to its nature the armor cannot be enchanted by normal means, but you are sure there are ways to improve its effectiveness - you just need to discover them.