Thank you for viewing. This is an insulator made of synthetic resin. The type of synthetic resin used for the insulator is unknown. This insulator was likely used inside a cubicle (box-type high-voltage substation) to insulate 6,600V high-voltage power lines. I purchased it at a "junk market" held at a nearby temple, and it appears to have been used for a long time, as it is quite dirty. There are no cracks or chips. It feels heavy when you hold it. I think it will become quite clean if polished. I think it can also be used as an object or decoration. This is a set of three. If you understand that these are old insulators and are interested in them, I would like to sell them at a bargain price. Please consider it.