Hemingray 42's might be the most common insulator on the planet, however, finding an absolutely mint fang 42 is nearly impossible. Of the hundreds of fang 42's I've handled in the wild for 50 years, no more then a dozen have I found in mint condition. The old Nickel Plate Road through my town was just loaded with them. This one looks like it just came fresh out of the mold with not even a flea bite. I never found one with all the drip points fully formed with the bead of glass at the ends.