External material TPU, environmental soft; PCM: It is a Phase Change Material developed by NASA to protect astronauts from sharp temperature deviations. This PCM gel freezes faster and lasts longer than traditional hydrogels, providing a constant temperature and comfortable cooling effect! The melting point of normal ice is 0 ° C, and the melting point of cooling ice tube is 27 ° C, which keeps skin surface temperature within a comfortable temperature range. * The cooling neck tube has the characteristics of high potential heat energy and large amount of heat energy absorption, so that you can keep a longer time of cooling. * Portable and reusable * No batteries or chargers are required and it freezes to use any AC! Automotive air conditioners, office air conditioners, home air conditioners, refrigerators, refrigerators, freezers * Maintain solid ice at temperatures below 26 degrees Celsius, both indoors and outdoors * Maintain optimal cooling temperatures without risk of skin necrosis or frostbite1: keep at the comfortable temperature of the human body, will not cause ice burns 2:2-3 hours of cool experience that can be recycled, melted uniformly and self-nucleated. 3: The use of new bio-based PCM phase change constant temperature material, low undercooling, temperature of 18℃, 22℃, 28℃, temperature can support customization. 4: Activation is faster and lighter than water. 5: Suitable for all kinds of temperature environment. 6: high strength TPU package, bearing pressure up to more than 200KG. 7: soft ring pad tightly fit, better provide cooling effect.Do not touch sharp objects, do not touch open flames