These drink bottles are made from 18/8 stainless steel. The Oasis Insulated Drink Bottles will not sweat and will stay cold for up to 20 hours and hot for up to 10 hours thanks to the double wall insulated design. They will not leak or leave wet marks in your bag or on your bench. They are a great sleek shape and size and will fit perfectly in your bag and take up minimal space on your desk. Cold and Hot times will vary depending on the temperate where you are. Made from 18/8 Stainless steel and non-toxic colour. Stainless Steel will not leach chemicals and the lids are BPA Free.