The water bottle with straw made by 304 Stainless Medical Grade Steel, very different with normal 18/2 stainless steel. Thermos water bottle is fully resistant to oxidation and corrosion. Also, the beverage can be kept with its original taste. This BPA FREE reusable water bottle will avoid the polymers, plasticizers and other synthetic elements. 304 Stainless Steel Superior Material: Made of 100% non-toxic BPA-free plastics & durable food-grade 18/2 stainless steel, protecting the water flask from oxidation and flavor transfer. How does it keep beverages hot? The air between two thin layers of stainless steel that make up the body of the mug is removed to create a vacuum. Because there is no air, the temperature on the other side of the wall does not transfer over, keeping beverages hot or cold for hours. Perfect for carrying around, whether it's at school, office, gym or outdoors. Specification: Material: 304 stainless steel inner tank + PP plastic shell Size: diameter 3.14in, height 4.13in, 10.1oz Color: 3 options Package includes: Water cup*3 Note: 1. Manual measurement, the size will have an error of 0.5-2mm, please refer to the actual size​​. 2. Due to the difference in light and screen, the color of the product may be slightly different from the picture. Made of high quality food grade 304 stainless steel, it's anti-corrosion and rust prevention. Used the vacuun-seal technology and double-wall construction, vacuum insulation for maximum temperature retention, keeping drinks hot for as long as 24hrs and cold for 6hrs . It's not easy to rust, corrosion and easy to clean Anti slip bottle bottom and the reinforcement bottom, make the anti-breaking performance more stronger, and the bottom used concave and convex design, make the vacuum cup steadily Insulated Double-Wall - Travel tumbler features dual walls with vacuum insulated, Keep drinks hot and cold longer for a more enjoyable drinking experience BPA Free Lid - The lid is chemical-free. it comes with a removable rubber gasket . Wide mouth design and Drink hole on the top for easy washing Fits Most Cup Holders - 10oz travel Mug lightweight and compact feel make it easy to fit into most car cup holders. Carry around your beverages whether home, office, picnic, hiking or camping adventures