I am not too sure if Durastar really fits in the cobrahead category, they really do not stand out well in a long row of real cobraheads.....they look completely different from a normal cobrahead. But yes it is fiberglass.... but again, its a strange weird design light.
the durastar,even though its shapped rather oddly,think about it really when i think of a cobrahead the westinghouse ov-25 and general electric m-400 fits the definition of cobraheads,cobraheads such as the copper ovm or ovx are boxier and look less like cobraheads.