Same Info here, just a better pic through a 16x loupe and whatever macro my cheap camera has. Still quite an unusual bubble. Check out the surface using " view original" Crazy rough surface that feels so smooth to the touch. ( I honestly thought they came this way when first posted ) I have a 145 That I assume is a No Embosing, American Product. My question is:(part 1) The base of this piece looks ground down, frosty, smooth. obviously a rougher texture than the.. smooth every where else on every insulator I've ever seen. Was unable to locate a pic on icon, (of a base). Was this piece made this way, or is my piece damaged? ANSWER: Yes!, probably from being a doorstop, riding around in a truck, or some such abuse. (part 2) If you will notice in the picture, at top, there appears to be a letter "R" INCUSED, not embossed.at least partial, enough to catch my eye in the light. I know we all see things we want to, and it could just be a 'fluke' bubble?, but the size and orientation are same as "R" in base embossed Am. Insulator Co. pieces (only they're embossed not incused.)-and yes it's a capital R in there.... ANSWER: It's a bubble, has bubbly characteristics, the insulator is full of bubbles, the surface of the "R" is the shiniest surface on the insulator, -kind of like...oh...say... maybe... the inside of a bubble???? Thanks Paul, and Chip!!