Around the city you find many different types of trolleys selling goods, food, juices... but almost all of them have the same structure. The frame is made using steel flat bars that are bent and twisted. Two pairs of ribs receive the wheels. Using four ribs instead of two allows each wheel to move independently. Over this frame a wood board made out of cheap wood battens is placed. Starting with this simple structure each owner can add parts to adapt the trolley to his own needs.