This insulator was the standard for telephone and telgraph for many years according to the National Insulator Association web page

Fizzy Hemi-Blue Hemingray -42 Insulator SHARP LONG drip points Hemingray 42s are fairly common, but this one is uncommon in color and character. There is not a single chipped or sliced drip point, however every single drip has a tiny bubble at the point (like the mold was not filled up). The dome has many indents, like something was in the mold. The insulator is very fizzy on the front side, but much less fizzy on the back side. There is a pinky nail size bruise to the upper wire ridge over the "A" in U.S.A. There is a tiny lower wire ridge nick just above "42". There is what looks like a light scratch inside the insulator, it goes right into the pin hole (also behind the "A" in U.S.A.).

Hemi-Green Hemingray – 42 Insulator round drip points This is another uncommon; common Hemingray -42. I find many aqua Hemingray 42s in antique stores. I pick-up hundreds of the common aqua to every single green. I call it Hemingray green because it is almost a light teal green. Under many lighting conditions these look like the aqua. Back-lighting them shows the difference in color. The minimial damage includes: a hard rub and flea bite to the lower wire ridge at the left mold line, four flea bites to the dome and a tiny bit of rougness to the inside of the petticoat.

Take the pair for $30 plus shipping.

USPS now offers "Ground Advantage" shipping which is considerably cheaper than the medium flat rate.