Hydro Flask's 21 oz. is the perfect go-anywhere companion on your busiest days. It stashes easily in a small shoulder bag, your pack's side pocket, or your car cup holder, and holds enough to keep you going for hours without weighing you down. The 21 oz. Standard Mouth is one of their bestselling vacuum-insulated water bottles because of its size and versatility. Versatile, middle-of-the-road size. TempShield insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hours. Durable 188 Pro-Grade Stainless Steel construction. BPA-Free and Phthalate-Free. Compatible with Standard Mouth Insulated Sport Cap. Flex Cap:. . Honeycomb insulation helps keep cold drinks cold and hot drinks hot. Durable, stainless steel pivots allow the strap to move easily. BPA-Free and Phthalate-Free. . . Lifetime Warranty. Holds 621 mL21 oz. 1.91 in. mouth diameter. 2.87 in. bottle diameter. 9.2 in. tall. Weighs 9.4 oz. Imported.