The mate cup is made of stainless steel, which is rust proof, high temperature resistant and corrosion resistant.It can be reused and used for a long time.The double walled feature makes it great for both hot and cold beverages, this double walled feature will hold the temperature of the drinks for a long time.You can also use this Yerba Mate Tea Cup with coffee or any other hot or cold beverage.This double walled feature will keep your tea set safe from damage.