No, they're not all the same. There are three types that I'm aware of:
Solid billet aluminum which I would recommend.
This thing, which I would not recommend:
And the Daystar kit which is made of a hard "rubber" compound. Again, I wouldn't recommend it.
NCD and PRG both use solid billet. There are several companies that make that thing pictured, and then there's the Daystar rubber one.