GUARDIAN 24 OZ AQUIFER is designed for active adventurers. Our stainless steel two layer construction has an air vacuumed barrier that minimizes the transfer of heat, keeping drinks at their ideal temperature and the vessel sweat-free. Cold for up to 24 hours and hot for 6 hours. The powder-coated 18/8 Kitchen grade stainless steel construction is free of BPA & Phthalate, cup holder friendly and dishwasher safe.  Sip-back cap makes beverage access easy and secure while the Flip-in handle makes it easy to carry and clip onto carabiners and keychains.