I have titled this picture "slippery surface" because of the particular design of the original Paderno (1898) developed by Ing. Guido Semenza. The first shed of this type of insulator is very steep and it is synonymous of ancient, (different from "newer" Padernos that have the shed less steep); in fact the first power line from Paderno d'Adda to Milan was equipped with similars to the big one. Until now, have been rescued only this two sizes of this type of Paderno. They have also the same head with the same slit, slightly enlarged at the ends. I have had the bigger one from my friend Guido (Thanks!) and comes from Abruzzo region; the small one comes from a village near Bologna.