Not only did Kerr make insulators, but they also made fruit jars. And, not only can you find a Kerr insulator with a cobalt blob in it (CD 155) but a fruit jar was also made with a cobalt blob. This jar is marked on the front Kerr / SELF SEALING / MASON. On the back, it is embossed, 65TH / ANNIVERSARY / 1903-1968. There is a 2 inch stripe of green in the jar too. Mint condition. There is also what I was told is called a "Monkey"s Swing" inside which is a piece of glass that goes from one side of the jar to the other through the center of the jar. Kerr sealing lid. but the ring that holds this lid in place is from another jar (a Classico lid). This is listed in the Red Book as #1387. $80 postpaid. Rick Soller, 4086 Blackstone Ave., Gurnee, IL 60031