3" Z-DENS Galvanised Locking Clamp

Z-DENS is an interesting system, being one of the few that will satisfy the new code concerning high-efficiency boiler exhaust venting; but anyone buying into it should be aware that the trade size (3", etc) is the interior diameter, and the exterior diameter is much less than that of PVC, so none of the commonly available PVC / rigid mounting solutions will work. Everything is proprietary. Very frustrating. These clamps are designed to fit around the bell end / socket of this system, and they DO NOT lock the spigot of the pipe to the bell end as do the ones which look like a worm-drive clamp. What they do is provide a rigid mount for the socket side of the pipe; the locking arms engage in the thin grove near the end of the socket. The actual application of this part is not covered in any of the installation documents that I've been able to find, and the instructions provided are pictographs; most unhelpful. Most frustratingly, one would assume since this is sold in North America that the threaded rod coupling would be in 3/8, in order to fit commonly available ceiling plates. It is not. It's 8mmX1mm thread pitch, which again is not mentioned ANYWHERE, and seems to be designed solely to fit the included lag screw, which is not pictured. Good luck finding a combination of parts to make this work with common threaded rod. You're better off finding an alternative mount if you're thinking of using this in an overhead / horizontal application.