Brand DOSHISHA Material Stainless Steel Color Black Capacity 420 ml Features Hot/Cold Insulation Target Age Adult A "Furu Furu" bottle that becomes cool and warm with just a light shake for 3 seconds. Cool and refreshing when shaken. The temperature of the drink is transmitted, allowing you to cool your body from the inside and outside. Shaking it cools the surface temperature. Warm and cozy when shaken. Even in freezing cold, shaking it makes it warm. Shaking it warms the surface temperature. The "Furu Furu" bottle has a hollow double-wall structure, so it is not a vacuum structure for heat and cold insulation. It does not have the function to raise or lower the temperature of the drink. Thank you for your understanding and purchase if you are comfortable with it being stored at home and being a used item.