In this system, the glass panels can be collected to one or more corners and it is carrying itself by only top profile. That is why the bottom case profile or rail is just 20 mm. So, there is no any roughness on the ground while entry and exit.
Also, it is allowable for the wheel transition.
Folding Glass Balcony System is moving only horizontal. That is why it shows the places more attractive and aesthetic. The system is being moving by two wheels which is on top of system. The bottom guides save the system balance and make the panels move easily to right and left side.