They attached a Canon XL1 camcorder to the lens. It say the EF adapter automatically adds a 7.2 multiplier factor to any lens, making this one effectively a 8640mm lens, and then they decided to add a 2x extender, results...
This doubles the effective focal length to a 35mm equivalent of 17280mm, yes, there are five digits in that number, which of course is utterly insane.