The appearance of Bars Box Ⅱ to Ⅳ is almost the same, however Bars Box Ⅱ (KW-37) had such a design.
The Bars Box series were decided from their appearance at first, and then were considered their mechanism later.
Did you already play in the Bars Box Ⅲ?
It is not the work with this cross decoration, right?
Ⅲ and Ⅳ were born by making the appearance simpler without thinking of gimmicks with the decoration of the cross.
Oops, Ⅳ will be able to move with this cross decoration design too.....