Then consider the size according to whether you need to carry it out. When you go out to carry or choose more than 500ml, you can avoid the embarrassment of drinking it in two bites.
The thermos is really a good thing.
First, it means good. Many people, even many enterprises, will send thermos cups as gifts. It means "a cup, a lifetime". So, you can send friends, family, employees and leaders.
Secondly, it is good for health. The thermos cup is indirectly good for your health. I once heard a medical expert say that boiled water is a very good skin care product. Drinking more boiled water is good for your health. There is a saying that "when people reach middle age, they still have to soak Lycium barbarum in a thermos." Isn't it the embodiment of the function of the thermos cup? So, if you love him/her, give her a thermos.
The thermos cup is developed from the thermos bottle. The history of thermos originated from 1892, which was invented by British physicist Sir James Dewa.
Heat transfer principle: radiation, convection and conduction.
The silver cup liner reflects the radiation of hot water, the vacuum between the cup liner and the cup blocks the heat transfer, and the bottle which is not easy to transfer heat prevents the heat convection.