warm double-deck bowl / tableware

Warm double-deck bowls are made of porcelain, there is interlayer
which can inject hot water in order to keep heating the food inside,
it is 2-3 times longer in terms of time compare to ordinary bowls. Hot
water is poured from the bottomopening and tighten the lid
afterward, it is convenient as well as enhance the product security.It has
the exactly same shape as ordinary bowls when you look at it in front and
easy to be packed up.