Features: No charger required It starts to freeze anywhere below 18C (64F). Just put this neck cooling tube into ice water. Is there no ice around you? do not worry Use any AC will freeze Car air conditioners, office air conditioners, household air conditioners, refrigerators, refrigerators, freezers. The cooling for time varies with the external environment, indoor 4-6 hours, outdoor 3-5 hours, by maintaining the best cooling temperature for cooling, there is no risk of skin necrosis or frostbite. Brand new coolant, no condensation, dry and cool, experience non-toxic fa-bric on your neck. Blazing and refreshing, long-lasting coolness, easy to carry, physical cooling takes effect quickly. Exercise rest, not easy to fall off, easy to wear and does not affect exercise. Specifications: Material: TPU Color: blue pink purple Size: 22x19x3cm Note: Do not for touch with pointed or for sharp objects. It is forbidden to for touch with fire or electric heating objects. This product will automatically freeze into ice below 18, suitable for summer, freeze in the freezer or refrigerator before use, and freeze for 15-20 minutes before use. Package includes: 1 Pcs Neck Cooling Tube.