I’d be carefull.
Depsite their claims, they can’t support the weight of heavier lenses/bodies. I thought to buy one as somethng I could pack while wading streams, bushwacking, on hot days when I didn’t want the extra weight of my tri or mono pod.
Went to the store, mounted my 1D and 180mm and it collapsed under the weight. One of those images above shows a Rebel XT with a 100-400 L or its 70-200 f2.8 IS. Both of which are heavy lenses.
I dont think it can hold the weight of a 100-400.
Can you use it?
Sure, but I wouldnt have my hands more than a few inches away.
J