They are fitted with AEG control equipment and Duewag bogies, have an additional door each side (for a total of three rather than two for the Z1 and Z2), and also had much smoother acceleration and braking performance, and improved suspension.
They are fitted with AEG control equipment and Duewag bogies, have an additional door each side (for a total of three rather than two for the Z1 and Z2) and drop down (as opposed to top sliding) Beclawat windows. They also had much smoother acceleration and braking performance, and improved suspension.