QUALITY MATERIAL: The main material of the product is silica gel, with a rotating bottle cap to prevent leakage. Designed to be leak-proof and resistant to high temperatures using advanced pressure shaping technology. Safe for microwave heating. NOTE: Fill with cold water and heat for no more than three minutes. SMALL AND PORTABLE: Dimensions: 10.3 cm x 16 cm. Capacity: 320 ml. Suitable size for adults and school-aged children. When filling, use warm water at or below 80°C. Fill to two-thirds capacity for best results. Keep away from children and avoid contact with face during use. SOFT HOT WATER BAG COVER: Comfortable, stylish, removable, and machine washable. Knitted cover provides improved insulation and helps prevent direct contact with hot surfaces. Safe for microwave use. Do not fill with boiling water. Keep out of reach of children when in use. MULTI-PURPOSE USE: Can be used for both heat and cold therapy. Heat application: helps soothe cold feet, non-inflammatory joint pain, muscle cramps, abdominal discomfort, and menstrual pain. Cold application: ideal for treating sprains, swelling, toothache, and providing cooling relief during hot weather. WARM GIFT FOR COLD NIGHTS: A thoughtful and practical gift for Christmas, birthdays, or New Year. Suitable for kids, teens, men, women, parents, and friends. Provides comfort during cold winter nights and can be used to relieve back pain and other body aches.