Is it just me, or is that just a copper tubing clamp with a locknut on it??
Dang, first someone beat me to the pocket fisherman idea, then the "shamwow", and now this.
Steve
But their hype about being the only approved method is horse hockey, IMPO.
An EGC should never enter the enclosure by itself. It must be run with the associated circuit conductors. I assume that the question is really asking about a GEC (grounding electrode conductor).
Ditto and the fact they try to lead people to believe that you need that product to comply with the NEC is enough to make me not to ever do business with them.