I tested with an APS-C Canon EOS 60D and various lenses.
The bag comes with a rubber ring, which comes on to the lens and to prevent scratching on the front wheel. This is also urgently needed, since it is made of very soft plastic and is already scratched by fingernails. So I had to use a recently (from wherever) deep scratches on it. The rubber ring can be attached well to Sigma lenses, since a bayonet catch for the lens hood is available, on which the ring is good. On a Canon EF 85 F1.8 the rubber ring, however, is not to fix and always slips down.
The introduction of the camera with lens is extremely fiddly (M size of the bag and Sigma 17-70 F2.8-4 should actually fit for description).
Zooming can be almost impossible because of the zoom ring is elusive and also with extended lens the windshield pocket suppressed by the flexible design of the tube.
At 17-70, the focus ring turns unweigerlch during AF with (as with many inexpensive lenses). Since indentations pocket press the focus ring, the camera can not focus frequently, the lens are then high-frequency, rather distressed-sounding noises. Certainly not good for the engine.
Most test shots were not really keen - even if the camera has focused correctly. At 100% view it looks as if "double vision" were added - speaks not just for the optical quality of the windshield. This problem is but _unter_ water probably not occur.
Looking through the eyepiece, triggering and set the aperture / time using the corresponding dial function well.
All in all I would recommend the camera bag just as a gag, ideally with an inexpensive (old) camera and a fixed focal length.
This review only reflects my subjective opinion and experience. It does not represent general opinion on this product.