Cooling function. This high-quality thermos bottle keeps coffee, tea, juice, or soda pleasantly cool or warm for a long time. The mouth-blown glass flask is made from double-walled insulating white glass. This design allows for optimal and long-lasting insulation through a vacuum and a special silver coating between the two glass flasks. When filled, the bottle achieves a heat retention time of approximately 24 hours and a cooling retention time of up to 36 hours. High-quality sealing rings and the reliable screw cap ensure long-lasting and dependable use. The thoughtful design also allows for one-handed operation.