Our Stainless Steel water bottles are made from 304 Stainless Steel and leakproof. It is vacuum insulated double-wall stainless steel. Keeps water cold for 24 hours and warm for 12 hours. 100% BPA free.CPS Approved. WAICEE is created endurable to the hottest summers. This is the perfect bottle for beach lovers, travellers as well as kids. You are going to enjoy cool water even under the hottest sun. The ability to keep liquids warm for 12 hours allows carrying your favourite hot beverages with you.