It is an electric truck by Maschinenfabrik Esslingen. I'm not absolutely sure what the right model designation is. My source, a German veteran truck magazine named it EL 3000, which I think is wrong. There is a contemporary picture with the hand-written caption EL 3002, which I can't confirm anywhere else. Two different books about postwar German trucks share another model code for this truck. Locked for you to have a guess.