This size is M. (Reference Information) The photos show a man who is 170cm tall and weighs 68kg wearing the item. (The size is L. It fits perfectly.) The size of the ice pack is a 15cm square. ■ Product Size (unit: cm) M: Shoulder width 30, Back length 25, Width at armpits 46 L: Shoulder width 30, Back length 29, Width at armpits 53 LL: Shoulder width 30, Back length 33, Width at armpits 57 This product, the "Cooling Vest (Ice Vest)," is an all-mesh innerwear specifically developed to be worn under work clothes or suits. With excellent breathability, it prevents a decrease in work efficiency due to heat stress and is ideal for heatstroke prevention. Furthermore, by using this cooling vest in conjunction with a fan-equipped work uniform, breathability is significantly improved, and the circulating air is cooled, allowing for more effective body cooling. The use of antibacterial and deodorizing materials allows for comfortable use for extended periods. The "Cooling Vest (Ice Vest)" is designed with ice packs placed on the back and under the armpits, sending cooled blood flow throughout the body and effectively preventing body temperature from rising. In particular, the adjustable shoulder straps allow for precise placement of the cooling packs under the armpits, effectively cooling major arteries and reducing the burden on internal organs. In addition, the close-fitting design ensures that the cooling packs are securely fixed to the body, not hindering movement even during exercise, and reducing fatigue. The drawbacks of conventional products, such as "stiff shoulders," have also been improved, achieving a more comfortable fit. This product is ideal for heatstroke prevention in environments where long-sleeved work clothes are essential, such as construction sites, agricultural work, warehouse work, and security work. It is also a reliable item useful for outdoor activities in general, such as fishing, BBQ, camping, and gardening.