This is the 3th (after this [id=370195800] and this [id=370761532]) very ancient insulator for electric power that I found on the same woollen mill. It has the Ginori's mark incuse on the bell. The fairlead on the top is very large, maybe developed for aluminium wires which have larger diameter than copper or iron wires. On the right the comparison with a normal 1U type for telegraph use. Very lucky strike!