Numbers:
Weight: 1000 tons
Length: 35 metres
Width: 14 metres
Height: 11 metres
Armour: up to 250mm of steel....
Armament: 2*280mm canons (yes-the same as the triple 28cm on light german battleships...)
Crew: 20-40
Speed: 40km/h (I think this is optimistic...)
There was also plans for two compartments with a BMW motorcykle for scouting.
Albert Speer stoppet the project i 1943, probably seeing the madness in it all, before a prototype was constructed. Seeing these drawings of its size, I can understand why-this thing would have been impossible to use in mobile warfare, its as easy as that, and its a hell of an expencive gun turret....
Theres some debate as to what the secondary armament would have been, suggestions are either flak-guns or 50-128mm anti-tank guns.
Its so big its beyond funny...
One suggestion on what it might have looked like
Heres another suggestion to what it might have looked like