The main elements of Otto system are:
Double cubes (100x50x40cm)
Single cubes (50x50x40cm)
Screws with nuts
All the cubes have in the corners (the double also in the middle) some dots ranging from 1 to 4, where 1 is the tallest and the lowest 4, they serve to indicate the height of the slots.
To be assembled, the cubes must all be fitted with the valve on the same side.
Where the slots do not touch each other, insert the spacer so the cubes are joined together.
To secure the cubes, the connectors are inserted into the slots and rotated by 45° with the appropriate key. To fix the outer perimeter, the screws with nut must be used.