In November 1942, Hitler and Minister of Munitions Albert Speer discussed possible launch configurations and examined models and plans of the proposed bunkers and mobile launchers. Hitler strongly preferred the bunker option, though he also gave the go-ahead for the production of mobile launchers. Two different bunker designs had been prepared: the B.III-2a design envisaged preparing the missile for launch inside the bunker, then transporting it outside to a launch pad, while the B.III-2b design would see the missile being elevated from within the bunker to a launch pad on the roof.