It is stainless steel, and it has stops so it doesn't collapse too far, making it difficult to open. Other than that, it pretty much is a car antenna.

I just received the data sheet from Live Fire on what their product is made of. It is lengthy, but the gist is that it has a wide variety of chemicals in it, and other substances. The sheet describes many handling hazards, which are not shown on their web site. Among other things it has:

Cellulose
Paraffin waxes and Hydrocarbon waxes
White Mineral Oil, petrolium naphthalene
Kerosine
pine oil
C.I. Acid Yellow 23
Bisphenol A-epichlorohydrin polymer

So maybe Blast can tell us a little about these things, especially when combined.