A sippy cup is a drinking cup for a toddler with a specially designed lid to restrict water flow so the child doesn't get too much water at once and potentially choke on the heavy flow. Our friends at Klean Kanteen have taken their original water bottle design and designed a sippy cap with the correct flow to use on the bottle. The 355ml bottle is still small enough for young hands to grab on to. The benefits of converting a water bottle into a sippy cup is a simple lid swap means you can have it leakproof for transport (sippy lids are not leakproof) and when your child is older, you can upgrade the same bottle to a sports lid. While the range only comes with the sippy lid by default in the 355ml single wall size, you can purchase an insulated water bottle in the Klean Kanteen range (they also start at 355ml in capacity) and add the sippy cap yourself.