Nylon BUILT FOR THE OUTDOORS – Stay hydrated while you explore the outdoors. Designed with a ribbed body for extra durability and easy grip. The powder-coated base provides resistance to tough conditions and the extra width provides stability 100% LEAK PROOF – The extra-wide spout features a stainless steel screw cap and silicone insert, designed to be completely leak proof, making spills and leaks a thing of the past VACUUM INSULATED & DOUBLE WALLED – The double walled 18/8 stainless steel offers long-lasting insulation, keeping your drinks hot for up to 12 hours and cold for up to 24 LIGHTWEIGHT DESIGN – Although this bottle boasts a large volume, it weighs only 360g! It’s easy to carry along on adventures or place in your backpack HIGH QUALITY BUILD - Designed for longevity using the best materials to make a sustainable product that can be used every day. The ideal accessory for those living a healthy and active lifestyle