Maximum Charge Tier: V: The maximum charge tier of this Rune Arm is Tier V.
Rune Arm Imbue: Force IV: Wearing this Rune Arm will imbue any weapon you wield, dealing 2 to 12 points of force damage per hit. This damage scales with 200% Melee or Ranged Power (whichever is higher).
Potency: Passive: +60 Equipment Bonus to each Spell Power. (Universal Spell Power is a different statistic.)
Protection +6: Passive: +6 Deflection Bonus to Armor Class.
Elemental Absorption -5%: This effect absorbs 5% of all acid, cold, fire, and electrical damage you would have taken, after all other protections have been penetrated.
Though you are not certain what this device was originally utilized for, it seems to be able to absorb elemental energy and convert it into pure magical force.