What a massive chunk of glass! It looks like you could reach down the throat of the lens and adjust the aperture from the inside.
From its appearance, that lens promises you could shoot a black cat eating licorice in a coal bin during a total eclipse and never leave base ISO. Heck, that lens probably caused the Great Northeast Blackout of 2003. Someone clicked off a shot wide open and sucked the light out of 13 states.
Cheers, Jock