Simple structure that is easy to keep warm, cold, and wash. Vacuum double structure that is resistant to condensation and enhances cold retention. A whole washable inner box. Smooth mouth with chamfers. Wide caliber for easy washing. * Do not add dry ice or carbonated drinks. material: Inner bottle, body, mouth: stainless steel lid, inner plug: polypropylene Packing: Silicone rubber size Length 9× Width 9× Height 10.2cm capacity Actual capacity: 0.31L Suitable capacity: 0.28L Cleaning Methods * Dishwasher and dryer cannot be used. Heat and cold insulation effect Heat insulation: 52 degrees or more (6 hours) 80 degrees or more (1 hour) Cold insulation: 14 degrees or less (6 hours)