In "Qpid," Riker and the rest of the senior staff go in search of the captain and Vash, when they find that Picard's execution by beheading is imminent. Riker, noting the number of armed men surrounding them, tells Data that the team needs a diversion. Data then removes a component from the inside of his arm and tosses into a nearby fire, causing a large explosion. Is there any information anywhere what this component was? Obviously it was either unnecessary or replaceable, but I'm not sure if its function was ever stated.