Ptero IV – 9871 is the 4th sculpure in Ptero series, private collection. Ptero series get inspiration from the Museum of natural History in Milano. The first, iron made, called simply Ptero, DVID 173, is inside AtelierFORTE at number 7703 . The second, Ptero II, DVID 24979, was exposed during the exhibition “Arkizoic Project”- 1583, in 2016 at Biologiska museum in Stockholm at number 1583-101 in the exhibition, now is in a private collection in Sweden. Ptero III, DVID 2467, after Storming of the Bastille at Reggia di Caserta, the exhibition in Rome at MAXXI and PTEPERO installation at MART in Rovereto now is in a private collection.