Reichminister Todt, and later, his replacement Albert Speer, both recommended the DB design to Hitler but a review by a special commission appointed by Hitler in May 1942 ended up selecting the MAN design. Hitler approved this decision after reviewing it overnight. One of the principal reasons given for this decision was that the MAN design used an existing turret designed by Rheinmetall-Borsig, while the DB design would have required a brand-new turret to be designed and produced, substantially delaying the commencement of production.[27] A mild steel prototype was produced by September 1942 and, after testing at Kummersdorf, was officially accepted.