Hydro Flask 21 oz Vacuum Insulated Stainless Steel Water Bottle, Standard Mouth with Loop Cap, Graphite Double wall vacuum insulated stainless steel water bottle keeps drinks cold for up to 24 hours and hot for up to 12 hours The inside temperature won't affect the outside temperature of the container that means no burned fingers from hot beverages or condensation from ice-cold drinks High quality colorful powder-coated matte finish exterior that never sweats Bottle fits in most car, bike and stroller cup holders and water bottle cages Tough, food-grade 18/8 stainless steel is BPA free and resistant to bacteria and odors