Fill the thermos to 3 cm from the glass neck. Do not use any hard objects inside the thermos. Do not use ice cubes inside the thermos to avoid breaking the inner glass. Do not use to store dairy products, baby formula, or carbonated drinks. Do not place the thermos in the microwave or dishwasher. After a period of use, the thermos may need to be polished to tighten the base.to tighten the base. Thermoses