I bought this to replace my NON-folding spiral. The old one goes over great with audiences. I used the new folding version this week for an audience of about 150 and NO ONE perceived the illusion. With larger audiences often a few can't see it. But no-one - ouch. I repeated it three times - each time with added embarrassment. The adult audience was clueless. The spiral seemed to slip in my B&D cordless screwdriver. Perhaps that was enough to ruin the illusion. I'll buy a wrench and Phillip's screw driver to tighten the spiral REAL TIGHT and see if that helps. But carrying that extra hardware sort of defeats the portability advantage. I improved the appearance of the prop by folding it up and carefully used a marker pen to make black sections of the fold to match the prop face. Would be better if Bruce made it that way or if the notes suggested this tip....