Product Category: Functional Underwear Top. Fabric and Chemical Fiber Blended Fabric. Suitable for gender neutral/both men and women. Quality grade qualified product. Suitable for sports, camping, fishing, traveling, hunting, cycling. Applicable age group: Adults. Is it hooded or not. Combination form single piece set. Whether there is an inner liner or not, there is an inner liner. One size fits all. Product Details A Peltier vest is a type of vest that utilizes the Peltier effect for cooling. The Peltier effect is the phenomenon of temperature difference between different conductors caused by current, and this vest achieves cooling by embedding Peltier elements. It is suitable for work or outdoor activities in high-temperature environments, and can quickly provide cooling effects to help users resist high temperatures. Peltier vests are usually equipped with rechargeable batteries and the ability to adjust cooling intensity, and some models also support use with air-conditioned work clothes. Attention: The measurement data of this product is sourced from the laboratory and is for reference only Refrigeration temperature (tested at ambient temperature of 25?) A. Strong temperature measurement of 4 ± 3? (temperature difference of -21?); B. Mid range temperature measurement of 12 ± 3? (temperature difference -13?); C. Weak temperature measurement 20 ± 3? (temperature difference -5?) In the laboratory testing process, “maximum -22? Cooling” refers to an ambient temperature of 25? , a cooling plate temperature of 3? , and a temperature drop of 22? . Derived from laboratory test results, for reference only.