Which brand of thermos cup has good insulation effect? What is the longest heat preservation time?
For the insulation effect of the thermos cup, the temperature can still be above 65 degrees after boiling water storage 12 hours, which is enough to show that the insulation performance of the thermos cup is good. The thermos cups produced by many small workshops can't achieve this effect, and only large factories can guarantee their high qualified rate, so you must buy brand thermos cups.