This set includes two kids tumblers and an additional straw and sipper that make it easy to prevent messes and spills. The screw-on lid fits securely, and the attached silicone straw has a valve that allows easy access to water, but will not drip even when the tumbler is tipped over. The stainless steel tumbler has double-wall insulation, which eliminates condensation on the outside, and has a capacity of 12 ounces. The plastic tumbler is lightweight and easy to carry, allowing you to choose the drinkware best suited to the situation. All the materials are durable, reusable, and made to last, as well as completely BPA free. The lid and plastic tumbler are dishwasher safe; the stainless steel tumbler should be hand washed. To keep the artwork bold and bright, we recommend hand washing. Do not microwave.