Klean Kanteen Classic Double Wall Vacuum Insulated Stainless Steel Water Bottle with Leak Proof Loop Cap Double Wall Vacuum Insulation, Keeps Hot up to 20 Hours, Keeps Iced up to 50 Hours Food Grade 18/8 Stainless Steel Construction Comes with BPA-free Polypropylene #5 cap Large 1.75 inch (44 millimeter) opening fits ice, easy to fill and pour; Compatible with all Klean Kanteen Classic caps Backed by the Klean Kanteen Strong as Steel Guarantee