It seems like a "popular" idea, see also this one:
The good guys over there must be not very familiar with units of measure or physics or both:
And it's so easy to use—just drop the card into a cup of boiling water (60 °C) for 3 minutes until it begins to soften. Then you can take it out of the cup and mold it into the shape of your choice.
at least here, water boils at 100 C.
Getting plain, white, pellets (and optionally mould them into a card sized shape) is of course an inconvenience (though hardly "painful") :
Normally, these types of thermoplastics are supplied in granulated form, which makes them awkward to use; the granules have to be squashed together, which is messy, wasteful and sometimes even painful.
(and its whiteness is a no-no, colour needs to be added (though I wonder if someone would go around with several such cards in their wallet to have handy the whole colour range).
Something like the above, polymorph
or Coolmorph (lower temperature):
is slightly cheaper, including postage (but hey it's in inconvenient pellets and no colour).