Such a handle bar improves your handheld video shooting because it allows to have a firm grip on your HF100. It has wings like the SteadyWing the professional black of the Fig Rig and the balls from the SteadyGrip.
I wanted a good looking solution and found a 350 mm wide and 10 mm thick black anodized bow handle at norelem.de. I also ordered other parts from them. You can find the part numbers in the drawing above. Since the 40 mm balls have a M10 thread and the handle a M6 one I also ordered two 10 mm / 6 mm Helicoil thread adapters. Unfortunately the thread adapters didn't fit. I found out that a normal M10 thread is M10 x 1.5 while those Helicoil adapters are M10 x 1.25. My solution made on a lathe is shown below.
The Quick Change Adapter is mounted from above using a M6 bolt with countersunk head. This required cutting a M6 thread in the middle of the handle bar and countersinking the adapter. Alternatively the Quick Change Adapter can also be fastened through a 6.5 mm hole from below using a 1/4" screw.
For mounting the balls I drilled a piece of M10 threaded rod and cut a M6 thread into it. There are also ready-made M10 to M6 thread adapters available.
Another interesting solution "to get a grip" on tiny camcorders like the HF100 is the Foddis Pico.