Easy to use: When using, you only need to inject cold or hot water according to your own wishes. Effectively relieve pain, suitable for sports injuries and physical cooling. The product can be reused many times and keeps cold longer than traditional cold storage bags. Safe and portable: 100% high-quality polyester fabric, safe and waterproof. It feels more comfortable when in contact with the skin. The folding design of the bag allows you to take it with you. Water-proof: The high-quality leak-proof cover with large opening, simple screw cap and safe closing system keep the cold and hot water bags well sealed. 2 How to use: As an ice bag: add some water and ice cubes, about 2/3 of the capacity of the cold storage bag. As a hot water bottle: Please use hot water below 50 degrees Celsius (140 degrees Fahrenheit). Size: Small-14 cm cool bag, perfect for children. Medium-20 cm and large-25 cm, perfect for teenagers and adults. Please note: If children use this product, they should use it under the supervision of an adult. Product description Specification: Material: high-quality polyester fabric, PVC and plastic. Name: ice pack, refillable and reusable hot water bottle. Size: Small about 6 inches, 600 milliliters. It is about 9 inches, 1800 cubic centimeters. About. 11 inches, 3000 cubic centimeters. Function: Practical helper for cold heat treatment. It is very helpful for children, women and men who exercise at home or outdoors. Quickly cool down and relieve sports injuries, reduce pain and reduce swelling. The cool bag can be perfectly adapted to different body parts. An important tool for first aid or clinical use. Simple application: Just remove the lid and pour warm or cold water. The lid is nice, easy to close and keep tight. Wash and air dry after each use. Notes: Not suitable for children under 3 years old. The inner lining of the ice pack is soft, so don't put sharp ice cubes in it to avoid damage. You can also add some water and ice, about 2/3 of the capacity of the cool bag. If you need to use it as a hot water bottle, do not use hot water above 50 degrees Celsius (140 degrees Fahrenheit).