Our Water Bottle is made of Plastic.The size is 16oz.It is lightweight, reusable, easy to carry, and has a high water flow rate. Our water bottles use a threaded lid with an up/down valve that seals your water bottle. It is very easy and intuitive to use. Just pull on the Valve to open the water bottle, and then push it down to close it. Optimized to fit into any water bottle cage, backpack pocket, or cup holder. The ergonomic design fits snugly in your hand and ensures you won't drop the bottle while drinking on the go!