Cellos Steel Series is made of thermo seal technology. With the Cello Flipstyle stainless steel water bottle with jacket, you can carry chilled water or the beverage of your choice with ease. Its Superior insulation performance-patented double walled vacuum technology and food grade material keeps beverages Hot/Cold for hours. This avoids re-heating saving time and being convenient. Taste and nutritive value of beverages remains intact for a longer duration which makes Flask an appropriate choice. Paired with a thermal jacket the bottle is eary to use, portable and extremely convenient