Forespar Masts

Ahoy All , After being directed to BCC Little Wing blog site , from this forum, I have a question that maybe someone can help me with.

Craig said : " If not for the double wall thickness of the aluminum at the partners, the mast would have sheared off at deck level when we were knocked down."

I did not know that Forespar made a double wall thickness mast at the partners.

Does anyone know about this ?