Hydro Flask 18 oz Vacuum Insulated Stainless Steel Water Bottle, Wide Mout w/Flat Cap 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 A great way to give back Hydro Flask donates 5% back to a charity of your choice The Lifetime Warranty makes Hydro Flasks the best water bottles