This 18 oz. powerhouse inherited double-wall vacuum insulation from its Rambler predecessors, carrying on the family legacy by locking in ice-cold water through backyard campouts and breaks between tag. As a well-deserved convenience for you, we made sure its Straw Cap (which comes included by the way) is leak resistant when closed and both the bottle and cap are dishwasher safe. Plus, its engineered with a super strong, stainless steel armor that wont flinch through bumps and drops on account of slippery hands.