Made of 18/8 food grade stainless steel, no BPA, phthalates, lead or other toxins * The 2125" stainless steel threads work with standard hiking and water filters * Made from healthy, recyclable food-grade stainless steel that is durable and reusable * Comes with a stainless steel loop cap for use with a carabiner or the flip d-ring cap is available as a separate accessory * Dishwasher friendly and easy to clean-no special brushes required