Vacuum Flask Stainless Steel 0.5L

Keep liquids hot or cold for longer, with the 500ml vacuum flask from Olympia. The flask's vacuum seal is specially designed to lock-in heat! Not only does this help to regulate your drinks' temperature, but also its flavour and aroma - allowing you to enjoy your hot beverages for longer, without losing any taste. Plus, the locking lid helps to keep your drinks that-bit more secure, whilst ensuring controlled pouring! This prevents leaking during transportation and makes it easy to pour a fresh coffee or cuppa. And completed with a cup that doubles-up as a lid, the flask is an excellent space-saving solution to carry in your bag or sit on your desk, whilst making it easy to grab a quick drink on-the-go. What is a vacuum flask and how does it work?A vacuum flask is a vessel that helps keep your hot drinks warmer for longer, and your cold drinks cooler for longer. It works by preventing heat leaving - or entering - the flask in three ways. Firstly, the inside is coated with a silver finish that prevents heat radiating out, or, in the case of chilled drinks, radiating in. Next, the double wall design creates a pocket of air between the inner surface and the outer one. This prevents heat loss - or gain - via conduction, which happens when two surfaces touch. Think burning your hand when touching a hot surface. That's conduction! The last way vacuum flasks retain heat is by stopping convection - or the movement of heat through gas or liquid. The airtight lid of a vacuum flask prevents this happening by stopping air entering or leaving the vessel.