The KOR Nava was designed to optimize water flow for easy sipping. Additionally, Nava"s filter is made from pure coconut shells. Coconut shells are widely recognized as the most effective material for carbon filtration, making them a renewable and health-safe resource. Our filters have been independently tested to exceed NSF 42 standards for chlorine taste and odor removal. Like all KOR Hydration Vessels, the Nava is made from BPA-free Eastman Triton polyester an FDA-approved, health-safe material that"s durable and beautifully clear. The KOR Nava hydration vessels are also easy to clean and easy to fill. A nifty spout twists off to reveal a much larger opening for easier cleaning and filling. The Nava utilizes our patented Easy Flow technology that eliminates squeezing, biting and excessive sucking - just sip naturally as you would from a straw. Our sleek designs include integrated, ergonomic handles that make carrying a breeze. Unlike most bottles, our hands-free push button cap design protects the mouthpiece from germs and dirt when not in use. Finally, 1 percent of all sales on KOR Hydration Vessels go to support critical water protection initiatives. Stylish, ergonomic, sustainable, responsible the KOR Nava has it all.