Invincibility (D20 Modern Equipment)
From D&D Wiki
When this is activated (a standard action), the creature or character takes no damage (with the exception of falling damage) of any sort for two rounds. The creature or character cannot be killed for the duration of the effect. Essentially, the creature or character becomes invincible for two rounds. Each invincibility can be used only once.
Invincibility has a purchase DC of 50, with a restriction of Mil (+3), and weighs 5lbs.