The thermos does not contain BPA. Insulation: Not sure if you can sleep well in the cold night, our silicone thermos will help you keep your body warm and comfortable. A thermos with a lid can keep warm for a longer time. You will get a hot water bottleand a knitted cover. Easy to use: wide mouth design, convenient to add water, take water when not in use. You can put it in boiling water. Silica gel is also resistant to low temperatures. So hot or cold water is fine Leakproof and air durability: There is extra rubber in big months to prevent leakage and overflow. Don't worry about water flowing out when using it. This hot water bottle can relieve pain: the cute hot water bottle is a home remedy. It can be used to treat muscle soreness, anti-stress, relieve aches and pains, relieve stiff neck, back pain, etc.