A rather solid off-camera flash bracket that attaches to an Arca Swiss plate. On my gear, I have attached it to the plate on the foot of my Sigma 500 f4.5. The bracket can be quickly removed as can the flash from the bracket via a clip arrangement. The only detracting feature is that the whole setup is rather tall.
Shown with K5IIS, Sigma 500 f4.5 APO DG EX, eBay flash cord, Metz 58AF-2 flash, Better Beamer FX-3 and Wimberley Gimbal Head.