Here is an uncommon common and recent addition to my CD 154 collection, a diamond CD 154 with round drip points. While it is easy to find diamond CD 154 insulators with a smooth base the round drip point type is considerably rare. In the last 15 years I have only seen one other offered for sale. This Canadian insulator was produced by the Diamond Glass Company which later, after merging with another glass house became the Dominion Glass Company.