[1000mp] coax line isolators or chokes

[Ronald Long]

Has anyone ever opened one of the Radio Works coax line isolators?
http://www.radioworks.com/clitop.html
What is inside? Is it like the choke in ARRL Handbooks with steel wool 
inside a tube?

I have what seems like a similar product CF5KV "High-Q Common Mode Choke" 
from rf inquiry of Japan. http://www.rfinq.com/

It seems to have helped rfi problems here, MarkV and 91-beta amp. They 
claim to have sold 20,000 to the Japanese market but don't mention sales 
numbers in USA. They give some interesting measurements on the web site 
which I had not seen before. Since it was kind of expensive I haven't 
opened it either. I hope it is full of ferrite washers and not steel wool!

ron w8gus.