This must be one of the sturdier of its type available. The side pieces are made of chromed, tubular metal and not of the same type of wire used for the baskets. Consequently, there is no play or movement once assembled. There are two screw holes (?) on the underside of each of the side pieces but there is nothing that may explain their presence. They may be for some type of hand grip but they are apparently not used.
Although assembly requires the aid of at least a third and possibly a fourth hand during the initial assembly stage, subsequently it can be performed by one person alone and needed less than 5 minutes in total. You could almost say that it takes as long to unpack as it does to assemble. Once the first shelf was properly installed, the unit becomes more stable and self-supporting provided that you follow the guide and work from the top down. Inserting and engaging the remaining baskets is then quite simple.
The four castors need to be inserted into their receptacles and need a little pressure to engage; a bash with the palm of one hand was quite sufficient for me but a light tap with a hammer or length of wood would work just as well for the less than heavy handed. I thought it best to insert these before assembling the unit.
Fully assembled, the unit is quite light and easily moved when needed. Even loaded with about 10kg of vegetables, it moved easily.
This unit is quite low and a fourth or even a fifth basket would not make the unit excessively high. 66cm is barely more than 2ft and therefore only reaching mid-thigh. The lowest basket is barely above floor level and you will need to kneel to reach the lower ones. For stability, heaviest items should be placed lowest and I have always used the bottom basket for potatoes and things like cabbages.
The trays are quite well-spaced and access is not a major problem for the more commonly used vegetables. Despite my comment about heavier items being best places low, a pumpkin for example, may need to be placed in the top as it may not fit lower down.
Sturdy, stable and not needing too much space. Recommended.