It is notable for the guaranteed resource cost reduction roll. As of patch 2.2.0, it also has a unique affix. While it may seem useless to most builds, since they are extremely unlikely to roll 5 consecutive hits without at least one critical strike, it is actually very powerful when combined with damage over time effects that cannot roll Critical Hits, such as Rend or Haunt. The only restriction is that the counter of hits is not reset until the guaranteed critical hit effect has worn off (to prevent it from having 100% uptime).
Stats (Level 29)
A great melancholy has been known to strike those who wear this ring. Archaic hieroglyphs inscribed on its band tell a tale of unrelenting heartbreak and sorrow.