18/8 Recycled stainless steel. Naturally BPA-free double-wall vacuum insulationFlowState™ 3-position lid with rotating cover for versatility. No splash straw quencher, open drink spout, or fully covered & close silicone sealed cover reduces spills. Reusable straw included. Lid disassembles for deep cleaning. Lifetime warranty. 5 HRS HOT / 9 HRS COLD / 40 HRS ICED.