This company I've found little info on. They started in 1924 and has a patent for a Drop wire Insulator US1,721,259. by William H. Pearl. They lasted sometime into the 1950's? I have several wire holders by this company but no spools or other. Would love to find a catalog and more info on them. I am still looking for the No. 100 (single) and 200 (double) Drop wire spool lags and the No. 300 lag tie off wire holder (rams horn shape). This picture shows the pieces I have. first is a heavy duty marked Pearl, Next is a Pearl/ 400, after that is the same with a patent number on back. The next one is Pearl /600 with pat on back, this one same different color, This one is more modern design marked Pearl/ 600 with Pat on back. The patent as on many insulators is for Line Materials lag screw in a porcelain body and was leased by many manufacturers. Second to the last is marked Pearl/ No.800, Last radio lag is just marked Pearl.