These type Insulators used in Hungary on small voltage distributor lines from beginning the electric works until about 1970-75.
These are very old types here. For the first street light used DG-3 types in Temesvár (today: Timishoara) at end of last century.
Now all Insulators changed to KT Insulators, these type ones are rare in use, but lot of house wall has 2 or 4 pieces without use.
There are the DG-2 and DG-3 Insulators, the most general in the old times. The glass signed the null wire, it is very rare.
These are the fat DG-s. I don't know why are them fat, but they were common the old times. The glass signed the null wires
The null signal glass Insulators CD-455s and CD-456. They are rare also
A Cyliner-head in old electric lines. The other is old urban electric Insulator
Old open fuse wire DGL-3 and DGL-5 Insulators. Two screws held the fuse wires, the two wire grooves were for the two circuits.
The DGn-2 Insulators, T-bars. Thes held the parallel wires with the pole or the wall.