Konjac block.
Those things are made of konjac flour.
They are all sold outside.
The taste is ok.
Special konjac silk. It tastes good. Like fine powder. But tougher than fine powder. It often appears in Guangdong cooking.
It's easy to get full after eating konjac. Therefore, the effect of losing weight is achieved.
But you can't just eat this. You will be malnourished.