The insulator has a logo of the Porsgrund (Norway) porcelain factory, which was rarely seen on insulators and produced high-quality utility porcelain. The production of insulators and other technical porcelain was moved to a new factory in Frederikstad in 1916 and its products have the NTP logo embossed, so the age of the insulator can be placed between 1885 and 1916. The insulator is without any damage, the price including shipping from Norway is 50 USD, PayPal preferred.