Magic Tricks

Thanks for the answer, and I knew that, but there is always someone who quickly attempts to do something they should not! Will consider this trick,,, but can see this kind of thing happening!!! Thanks Again!! Dan

The truth is that it has never happened to me. I usually control the situation and it is not easy to break Unliftable with this new system and normal use. Iñaki

Everything Ashburn answered is correct, thank you.
If they apply a lot of force, they can break it, just like they would break anything else.
We advise against presenting it as a strength challenge. Iñaki

Some years back this was sold as an instant download with instructions on crafting your own gimmick. I made one and the gimmick worked great but when I tried it for a friend he pulled hard enough to break the box. I have no idea how much sturdier the gimmick they're now selling is compared to the one I made using a regular tuck case, but if it's still cardboard I assume there must be the possibility it will break if someone pulls too hard.
I never got around to constructing a second gimmick but I think to minimize the chance of the spectator breaking it, particularly if it's someone that looks strong, very specific instructions should be given. For example instead of telling them to simply try to lift it, instruct them to first lift the box using just one index finger of each hand on opposite sides of the box. Not sure but this seems like it would make it impossible to get enough leverage to pull hard enough to break the gimmick. Either way I think it will take some audience management skills but the secret itself to this is very cool and I likely will buy it.