NoteThis product is NOT a Heater that can quickly heat up a baby bottle, just a low-voltage USB insulation bag to keep warm. It heats up slowly, suitable for long-term wrapping to keep warm when you are finished feeding your baby, or when you are not in a hurry to feed your baby. Use this product to wrap and keep warm for use. If you need fast heating, please look for other styles of products, please understand before buying, thank you. Three Levels of Adjustable - Only Keep WarmerThe Baby Bottle Warm Keeper just keep warmer, it can't heat the cold milk. Three levels of adjustable, temperature adjustable, not hot, you can adjust the required level according to the seasonal temperature, the highest level is about 60 , the middle level is about 50 , the low level is about 40 . ConvenienceBottle warmer can make night feeding more relaxed, more steps of traditional milk, baby can not wait, parents lack of sleep, warm milk cover easily solve the trouble of father and mother. Lightweight and portable, convenient to carry when you go out or travel, give baby warm food anytime and anywhere. USB Milk Bottle Warmer Bag with a strap is portable and can be hung on the baby stroller. Outstanding PerformancePerfect solution for parents to conveniently, safely and easily warm baby bottle while in the car traveling. This is a thermostat, not a heater. If you need to maintain the temperature of the baby bottle, you still need to have a water temperature of about 50 when making milk powder before you can use this product to maintain the temperature. Suitable for Various OccasionsSupport cars, mobile phone charging lines and mobile power supplies, plug-in can be heated at will. Small and compact design is easy to carry and store, takes up little space, and fits in a suitcase.