TempShield insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hours. Large size for longer adventures. Fits most backcountry water filters. Durable 18/8 Pro-Grade Stainless Steel construction. BPA Free and Phthalate Free. Compatible with our Hydro Flip Lid and Wide Mouth Straw Lid. Dishwasher safe. Flex Boot for added protection and traction on slippery surfaces.