Number of Layers (Specifications):

Domestic double-layer [1 panel 2 plastic plate 4 wheels]]

Domestic three-layer [1 panel 3 plastic plate 4 wheels]]

Domestic four-layer [2 panels, 4 plastic plates, 8 wheels]]

Export double-layer [1 panel 2 plastic plate 4 wheels]]

Export three-layer [1 panel 3 plastic plate 4 wheels]]

Export four layers [2 panels 4 plastic plates 8 wheels]]