Rambler Jr. is a small-and-mighty kids bottle over-engineered for your little wild ones. This 12 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. Plus it's engineered with a super strong stainless steel armor that won't flinch through bumps and drops on account of slippery hands.