Critical Chance vs. Low Health
Increase your Critical Chance against enemies below 40% Health by 4%
Where to get
Show on the tree It opens the Gloom Stalker tree.
It opens when any one of the nodes it needs has a point.
Numbers
TreeGloom Stalker
Crit Chance vs. <40% HP+4%
Critical Chance vs. Low Health
Phantom Sharpshooter