First of all, these dice are not the least bit examinable. You can indeed force the number you want,
but you'll have to do a switch if you want the spectator to handle the dice first. Granted, these
are dice, which are probably one of the easiest props to finger palm and Bobo switch so that
shouldn't be a problem, but it's worth noting.
Also, you can only force one number per
dice. Meaning if you need to force a 3 and a 2, you'll have to do two switches. Again, not
impossible, but worth noting.
Also, you'll have to perform this using an opaque cup so they
shake the dice in the cup and look down into it for a number. You can't roll these on a table
without the method becoming blatantly obvious.
For the right effect with the right
audience management, this will work. To me, it's overpriced though for something like this.
The ad clearly states you must switch out the die if you want it examined.
As the reviewer said, an experienced magician can do this easily.
This is a good direct way to force a desired number 1-6.
If you'd like a more examinable die, then I recommend my 7 Lucky Dice Set or individually sold as Forcing Dies. These look more normal and force the number using the process of elimination.
These dice are exactly as advertised. No, they can't be handed out for examination, but with proper audience management and the tiniest bit of sleight of hand (done well, obviously), your spectators will have no reason to believe that these are not completely legitimate dice.