I'Z Peltier Vest Set III, which utilizes Peltier cooling technology, provides comfortable temperatures. - Product Name: I'Z Peltier Vest Set III - Cooling Technology: Peltier cooling - Battery Capacity: 10000mAh - Size: L - Supported Temperature: 22℃ - Brand: Linnxas Thank you for viewing. The box has been opened, but the rest is unopened. It is new and unused. As shown in the photos, the box is damaged, but there are no issues with the contents. Includes a battery. Please refer to the photos. Thank you.