Klean Kanteen Classic Single Wall Stainless Steel Bottle With Leak Resistant Sport Cap 3.0 Durable and High Quality 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 Easy to clean electropolished interior doesn't retain or impart flavors Backed by the Klean Kanteen Strong as Steel Guarantee