The document describes several unusual inventions called "chindogu" which are meant to be absurd or impractical devices. It lists a biking accessory, Roman chair for abs exercises, oversized pillow, swinging chair, cooling jacket with cold jelly bags that solidify when heated, and suggests the first chindogu invention is free. The devices are intended as jokes rather than serious products.
6. Cold jelly bags
A jacket
The interior is originally solid. It gets
cold and liquid after squeezing it. It
returns to its original form after
heating it at 100属C and letting it rest for
two hours.