Collectibles--General (Modern)/X1 brookfield


X1 a
X1 a  

X1 b
X1 b  
Greetings Mr Berry.  I am trying to find a value for a Brookfield X1 insulator. It appears to be unused if that impacts the value. Any information you can provide would be greatly appreciated! The images I attached were taken in front of my screen to help pull out the details but if this isn't helpful, please let me know.  


Hi Ruthie,

We identify your insulator as a CD 102.  Insulator collectors have developed a numbering system for the various styles.  I'd date this from the early 1900s.  Brookfield was based out of Old Bridge, NJ and was in business from the 1860's through 1922.  I suspect that your insulator was used but sustained no damage in use (not too unusual for these rugged glass pieces) -- we would classify a piece like this as being in mint condition (no damage).  These are pretty common as they were used by the millions so do not have a high collector value - figure $2 or so.  These are still great pieces of communication history being well over 100 years old!  The X1 on the dome is a mold number - these were used to track production. Hope this helps

         Thanks, --Bob

Collectibles--General (Modern)

All Answers

Answers by Expert:

Ask Experts


Bob Berry


Questions related to collecting Glass Insulators and porcelain insulators - I can provide historical information as well as current collector values. I am also interested in purchasing insulators I need for my collection.


I have collected since the early 1970's and have much historical information, as well as knowledge of current insulator values.

National Insulator Association (

BS & MS in Electrical Engineering

©2017 All rights reserved.