SMART DESIGN: Double-walled vacuum-insulated technology keeps liquids cold for 24 hours and warm for 12 hours. Each sports water bottle has an airtight and secure easy-twist cap. LIGHTWEIGHT: Fits into a gym bag, bottle cage, cool bag, lunch box, car cup holder and rucksack. Can be used to hydrate for travel, work, gym, camping, sports, in the car or simply at home. HIGH-QUALITY MATERIAL: Stainless steel grade SS304. This is a high grade and once washed out does not keep odours. Not all flasks are the same! PERSONALISATION: This product provides a great blank canvas to explore your creativity. Perfect for laser engraving, crafts and much more. This model has no logo. EASY TO CLEAN: simply wipe the surface with a damp cloth or run under water. Not suitable for a dishwasher in order to preserve the quality of the product.