I purchased these two strains a while back because I thught they were neat and because of the embossing on them. They are different embossings and obviously different manufacturers by there shapes and embossings. What gave me a sort of brain bulb was what would make me buy these insulators if I were a company looking for insulators on my electric line. There is no manufacturer markings as to who made them but they had the magic word embossed on it. PATENTED. Patent is described as a grant by a government to a patentee as evidenced by an official document of exclusive rights to the subject matter or invention claimed to the patent. Basically meaning this was good stuff. Back in the day when advertising was more than just a comercial readily forgotton, to have a patent was a garauntee that this thing was good and worked. Many companies used this phrasing such as Patented, Patent Applied For, Patent Pending or a Patent with numbers and dates as Fred Locke was famous for on his early markings. Whether they had an actual patent or not, just that wording convinced a company or individual to purchase their product making it one of the best advertising phrases available in that time period. Just food for thought. Comes on some neat insulators too.