The outer cup made of plastic or stainless steel.
Next, for a cold insulated bottle, add the insulation is foam in a liquid form is sprayed into the space between the cups and allowed to harden. And for a hot-insulated bottle, in the space between the cups is vacuum, a large vacuuming machine sucks the air from the space between the two cups. And the top has a stopper can be pulled upward from the cap. Liquid flows through a small hole in the stopper