Heat Retention: Vacuum flasks is designed to extend heat retention for 24 hours. Hence ensuring to keep hot liquids hot for an extended period and cold liquids cold Double wall Insulation: Vacuum flask have a double-wall construction with a vacuum layer between the inner and outer walls Ecofriendly: Help the globe stay green one sip at a time with our eco-friendly vacuum flask Spill-proof lid: Flask comes with a secure, airtight lid to prevent heat or cold loss and to prevent spills Odour free: The inner lining of the flask is made from stainless steel which is resistant to staining and doesn't retain odors