Orb of Infinite Depth

Orb of Infinite Depth is a Legendary Source for the  in Diablo III, added in patch 2.4.0. It requires character level 70 to drop.

The unique affix applies once per cast, provided that cast hits an enemy. Both damage and damage reduction are multiplicative to other similar effects. Note that with Chain Reaction rune, each cast counts as 3 different hits, so it applies 3 stacks, provided all of them hit an enemy.

Number of stacks (and duration) will be displayed on the skill icon of Explosive Blast.