His suit is 75% Nomex to prevent him from catching on fire and 25% stainless steel thread, which creates a faraday cage around him that pumps about a half a million volts around him at all times. The steel allows the electricity to flow around the outside of his suit, completing a circuit, but none of it touches him.
The best part of this video? The quote at the end: "There's only three things I've ever been afraid of: electricity, heights, and women. And I'm married." Kudos to you, my friend, for facing all three of your fears. [Neatorama]