Experience the magic of color changing cups with Ello's 4 pack of 16oz tumblers! Just add iced beverages to the cup and watch it instantly change color. These tumblers feature lids that twist on and stay put, and a straw that's perfect for sipping water, smoothies, tea and more. The dual-action lid lets you drink from the straw or directly from the lid. All parts are top rack dishwasher safe and BPA free. Do not microwave or freeze. Not intended for use with hot beverages.