Caring for your Klean Kanteen properly can ensure that it will last a lifetime. Of course, that means keeping up with the maintenance it requires. Klean Kanteen bottles are made of 100 percent 18/8 food grade stainless steel, and caps are composed of a variety of BPA-free materials. The Sport Cap 3.0 is made of food grade silicone, and is designed for easy cleaning and replacement. Take a moment to watch the video above, which gives a detailed account of how to thoroughly clean your Sport Cap so it's in the best shape possible. Happy Hydration!