The Mengs double clamp is very well made and also holds a 5DIII very good with battery grip. I run this double clamp together the Mengs BPL 180 Panorama bar on my Arca Swiss compatible Sirui ball head as small panoramic Nodalpunktlösung. That's enough for single row panoramas that I can do on edge even without battery grip, because I still have a small L-shaped bracket of Mengs here. The 90 degree holder does not seem to be with millimeter precision, I have a Mini deviation, but I still can tolerate. For professionals eh comes the Nodal Ninja or Novodlex products in question, but for me the occasion and with little space claim plus light weight a great solution!
