Hello Owen,
I have tracked the product down to Jaycar but they don't know anything
about the material. The person I contacted was very vague and couldn't
steer me towards anybody that would know what material it was. All I
want to know is if the toroids would be any good for HF 1:1 baluns. I
have just made a balun using a FT-140-61 which is very close to the
same dimensions as the 2 toroids in the Duratech packet. If they can
be used they are a fair bit cheaper than sourcing FT-140-61 toroids.
In reply to Richard Clark, yes I do have a SWR meter.
Cheers
Max