Quite simply as the title says this is the best force bag currently on the market. It is elegant looking, does not look gimmicky or like a magic prop at all and I can say for sure that this will be going into my parlour set right away. I previously used an electronic device for the kurotsuke routine but there is obviously the potential for that to fail so with that in mind I can see this replacing that.
As regards to the spectator holding it, personally I'm not sure why I would do this anyway however I would be quite confident in letting them hold it for a few moments with no worries. Again though I don't think this would really add anything to the routine though.
If you use a force bag in your routine or are thinking about using one, this is the one to get.

This bag is a very professional-looking prop. It has a black satin-like finish that really looks good. There is one effect included using poker chips that is a nice way to get used to using the bag. This is a great choice for a change bag for an adult audience as the ones with the wooden handles just seem too much like a prop. This looks more like a small pillowcase.

Unfortunately, I see no way to give this to an audience member to hold. While the magnetic closure (it's in the description, I'm not giving anything away here) does hold well, the magnets he chose are thick and obviously stand out on the back side. You can easily hold the bag facing the audience so they never notice the magnets, but put this in an audience member's hands and they'll see it straight away.

The price on this is a little high, but not too much. The switch in this bag to the other pocket isn't too hard, but you'll have to move around to make it work. It's a little noticeable at the top. But if you need a change bag and don't want it to look like a gimmick, this is the way to go.

an elegant object made ​​with high quality materials (fully opaque and pleasant to the touch) that the system will be absolutely imperceptible to the public and also for the volunteer who assists the performer.
essential to "free" choices suited to be carried everywhere, both in close up in that parlor.
a truly foolproof method, safe and reliable!