The Constricting Ring is a Unique Ring which is randomly found in Diablo I.
It boasts an impressive 75% Resist All (displayed as MAX on the character screen), however the constant loss of Life more than overcomes this advantage, therefore making it impractical for constant use (so it is best used if it were to be equipped before engaging in battle against a foe with strong elemental attacks).
One should be warned of that this effect can and will kill a hero/heroine if he or she does not receive Healing in time, although this is negated when the hero or heroine is in the town of Tristram or has the Mana Shield Spell activated (the Ring will then eat of the hero's/heroine's Mana instead of Life, until their Mana is completely drained).
Stats

Constricting Ring
- +75% Resist All
- You constantly lose Hit Points (1.25 Life/sec)
- Quality Level: 5
Diablo I Unique Rings — Bramble • Ring of Regha • The Bleeder • Empyrean Band • Ring of Truth • Ring of Engagement • Constricting Ring
Hellfire Unique Rings — Giant's Knuckle • Ring of Thunder • Ring of Magma • Ring of Mystics • Karik's Ring • Xorine's Ring • Gladiator's Ring • Mercurial Ring