Feature: Size: 16x10.5cm/6.4x4.2" Material: PVC High-temperature and high-pressure forming technology, 150℃ high-temperature forging, secondary forming, no clogging, no pressure on the car, eliminating safety hazards from the source Can be put in the refrigerator: cold heat dissipation, can withstand low temperature -40°C, the refrigerator is filled with water and can be used for low-temperature refrigeration and cooling. Explosion-proof and waterproof structure design: 1. Large thread design, tight joints, no dripping 2. It is difficult to make the water injection port, and the plastic and silica gel are tightly combined 3. Large water storage capacity and longer temperature 4. Integrated mold design, uniform wall thickness Package Included: 1 hand warmer (excluding water) Notes: 1. Do not use for children under 3 years old. 2. About baby and kids safe. an adult should always supervise and never fill with boiling water.