Manufacturer: Hakukin Kairo Co., Ltd. Country of Origin: Japan Body Material: Brass Size: 68 x 101 x 15mm (thickness) Heat Retention Time: Approximately 24 hours maximum Set Contents: Body, Cup, Special Bag, Instruction Manual Features ・Approximately 24 hours of heat retention with 25cc of lighter fluid ・Approximately 13 times the heat output of disposable hand warmers ・Warms you from the core of your body with far-infrared rays ・Can be used for many years with proper maintenance ※ Please refer to the manufacturer's website for details. The product has been opened once for photography purposes.