This last page of insulators was surprising as well. I've never seen just a Square D Co. marked spool. They made lots of spools, wire holders strains and such for companies like Hubbard & Co., National Metal Molding Co., T.C White Co., Ohio Brass Co., Oliver Iron and Steel Co.,Automatic Electric Co.,Dongan Electric Mfg. Co. and Signal Electric Mfg. Co. to name some. It showes a radio strain, which I happened to have, but is not marked. And a cut out switch. I was dissapointed that it did not show any spools etc. that I have with just the Square D logo on them. Perhaps in another catalog. I was just very lucky to get this one.