WindCore's ICE x COLD cooling wear with instant cooling function, a vest-type design capable of cooling up to -19°C. - Brand: WindCore - Maximum cooling temperature: -19°C - Product name: ICE x COLD Cooling Wear - Function: Instant cooling - Design: Vest type I purchased this last year. I am listing it because I tried it on indoors and confirmed its operation, but then didn't use it. Of course, there is no sweat or anything attached. I have confirmed that the battery, fan, etc. are working properly. Thank you.