Hydro Flask Insulated Stainless Steel Water Bottle, Wide Mouth, 18-Ounce, Acai Purple Double wall vacuum insulated stainless steel water bottle keeps drinks cold for up to 24 hours and hot for up to 6 hours Premium grade 18/8 Stainless Steel BPA free Sports Bottle High quality colorful powder-coated matte finish exterior that never sweats The Lifetime Warranty makes Hydro Flasks the best water bottles