Smack 'em. - Improved crosshair accuracy while firing. Greatly increases elemental tech level (if element is available), allowing the elemental effect to occur multiple times under sustained fire. Doesn't seem to have critical hit bonuses as widely believed.
Mechanics
For technical details regarding this item see: Mechanics
Trivia
The red text may be a reference to the famous song "Smack My Bitch Up" by Prodigy.