An Inert-screen load shifter was a droid used around 4 ABY in engineering facilities and interstellar shipyards to transport quanitites of lethal fissionable material. It's basic design consisted of a large shielded container, with a simple electronic brain, mounted on a pair of short stubby legs.
Around 0 ABY, in an ill-conceived attempt to implicate the Falleen Prince Xizor in the deaths of Luke Skywalker's aunt and uncle, the Kuat of Kuat placed a highly-modified inert-screen load shifter near the Lars homestead, on Tatooine. This droid contained surveillance equipment to record the tragic event and a false recording of Xizor's pheromones to link him to the murders. This droid eventually fell into the hands of bounty hunters Boba Fett and Bossk.