The 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 the bestselling vacuum insulated water bottles because of it's size and versatility.Product BenefitsVersatile, middle-of-the-road sizeTempShieldTM insulation eliminates condensation and keeps beverages cold up to 24 hours and hot up to 12 hoursDurable 18/8 Pro-Grade Stainless Steel constructionBPA-Free and Phthalate-FreeCompatible with Standard Mouth Insulated Sport CapLifetime Warranty