MAYIM HYDRATION Kids' SipBuddy Tumbler Keep kids’ favorite drinks ready for the day with the Mayim Hydration Kids’ SipBuddy Tumbler. Its vacuum-insulated design helps maintain hot or cold beverage temperatures, while the dual-function lid offers the choice of drinking through the straw or directly from the sip opening. A leakproof design, convenient carry handle and cup holder-friendly shape make it easy to bring along, and the dishwasher-safe construction simplifies cleanup.