I actually purchased this exact box, not from eBay but from their actual retail front at https://www.thecinecity.com.
It’s not bad. The flag, mounts and parts of the box are all aluminum or sheet metal, but the actual box is hard plastic. It comes in 3 pieces, the mounts, flag and box. The mount just screws onto the front of the lens where a filter would go, and the box tightens around it.
Now, they have it mounted to a VX2100 in the picture. I will say this…it is better suited for a fixed lens camera. I bought it and 2 mounts, one for my 7D and one for my VX2100. When trying to focus with the 7D, it adds weight to the lens if it breaths while focusing and makes focusing a bit tougher. Since it can be untightened quickly from the mount, it’s best to focus, then tighten it back on.
As for the company, they were great! Correspondence through e-mail was fine, shipping was a bit high, but it is coming from over seas. The good thing with shipping from them is it took 3 days. I can order stuff 2 hours away from me and it could take a week or 2. I ordered on a Tuesday evening, I got it Friday morning.
Hope that helps!
-Chris