The Insulator sippy cup is manufactured by Playtex. They are generally sold in 2-packs (either 6 ounce or 9 ounce) and are readily available at most discount and baby stores. The colors and patterns are designed for boys, girls, or are gender-neutral. The cups have an inside valve that not only regulates the flow of the liquid, but also prevents most
leaks.
These cups, hands down, are absolutely the best sippy cups on the market. A lot of thought went into the design of the valve system it is strong enough to form a seal when your child is not drinking, yet it is also flexible enough to be used by very young children. Children as young as 6 months ...