The CD 145 "B" was a very common insulator used on every Central of Georgia Railway telegraph line. I think I must have over 20 different mould variations, single Vs. double "B", and almost every color from aqua to green. This includes lime, yellow green, olive, and the unique deep amber swirled item shown in the photo. In addition, there were CD 145 "B" in light SCA which I found on the Central of Georgia line near Albany, GA. Except for the SCA and some of the green shades, I could not give a CD 145 "B" away in a trade. This picture was taken with very strong backlighting, but I still could not get enough light to pass through it to show the embossed "B" on the front skirt.