Commissioned by the City of Milan as part of the renovations of the Milan Cadorna railway station, and unveiled in February 2000, the sculpture is made of stainless steel and reinforced plastic, painted with polyester gelcoat and polyurethane enamel. The "knot" is placed in the middle of a fountain on the middle of the square while the sewing needle is on the footpath in front of the train station. According to the artists the needle pulling thread through fabric is a metaphor for a train going through a tunnel. The thread wrapped around a needle also "paraphrased" the city emblem of a snake coiled around a sword. According to the City of Milan it is also meant as a tribute to Milan's influence in the fashion industry and the three thread colours (red, green, yellow) represent the lines of the Milan Metro.