This insulator was listed by Bob Berry in the latest issue of Crown Jewels as a CD 391 from Russia. I got one in 2005 from Ireland from the supply crates behind a power company garage. They are new and used all over Ireland on medium voltage primary circuits. They were in crates next to crates of larger 3 part glass multiparts that are used for high voltage primary circuits. The larger ones were marked Dielve which is an Italian manufacture. Although the 391 has no name on it, it appears to be the same glass and manufacturing style as the larger mulitparts. Mr. Berry told me that someone told him the 391 was from Russia. Does anyone know if 391s were found in Russia?

The picture shows two 391s in use near New Grange, just north of Dublin.