The Ju 87B series was to be the first mass-produced variant. A total of six pre-production Ju 87B-0 were produced, built from Ju 87A airframes. Test flights began from the summer of 1937.
The Ju 87B-2/U4 is the B-2 with the skis instead of the three landing gear wheels, the skis were installed by the field factory when front line units required this.
