These glass insulators are often seen on old buildings, and were pretty standard for most of the 20th century. You can use them to add small spalshef of color to a facade, and they are a great way to add wiring detail.
The block you get comes with 90 insulators, 3 sets of 30 pieces. Each set is a different style. 3D printing technology allows each insulator to be pre-drilled, something not possible to do at this price using other technologies.
This set is also available in 1:35th and 1:24th scale, and can be made in other scales. Please contact me for availability of other scales.