It is a patented (on Google search W.I.P.O. Andrea Belli) economical electrical trolley capable of climbing steps and stairs and of carrying person. It is all constructed of wood, nuts, bolts 3d printed parts and equipped with two windscreen electrical motors in house.
If this trolley was made of steel or alluminium it would be cheaper and it would solve the problem of climbing steps and stairs. The difference between this type of trolley and the others is that this trolley can go electrically forward and backward with the wheels locked in normal position (the others do not do it) , and, only in the case of climbing stairs, the wheels can become gears.

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