I 490's have mould numbers, which leads us to believe that these were all made prior to 1930, since mould numbers on AGEE insulators were well established by 1930. They were produced in a rainbow of colours, including greens, grays, blue grays, and several shades of purple, from light to dark until 1937, when straw colored 422's were introduced for the first time. I AGEE bells began having problems almost from the beginning of production. Because the glass was thin from the wire groove up, the insulators were subject to fractures in the neck area. And, as stated above, the shallow wire groove rims were nearly useless.
Glass colours range from light to medium to rich deep amethyst.
Mould numbers are embossed on all of these Type II bells. But there was still room for improvement, so Type III 490's were introduced in 1930 as the glass Trunk insulator of the 1930 to 1942 period. While maintaining the raised inner skirt of the Type II bells, this new style proved to be more structurally sound with its wide angular dome and thick angular wire groove rim. Those units carrying the 30 date were all medium to dark purple. This 30 did not necessarily mean the insulator was manufactured in 1930, but rather from 1930 to 1937.