This is a 3d replica, 1:1 ratio, model of the helmet worn by the character Lord Starkiller in the Star Wars: The Force Unleashed video game.
Galen Marek had killed Darth Vader and became the Emperor's apprentice, he would have become Lord 'Starkiller' (also called Darth Stalker by fans occasionally). When he finally gives his loyalty to the Emperor he takes over Vader's position as the Supreme Commander of the Imperial Fleet and the Executor. After having been crushed by the Rogue Shadow his right arm, which he used to contain part of the impact of the ship, was cybernetically reconstructed. His helmet contains some of the most advanced technology in the Empire, even capable of resisting light saber strikes. His first armor was the so called Sith Stalker, later he used an armor more reminiscent of Vader's, the Dark Lord armor