Enjoy instant filtration, ultimate convenience with our Water Purifying Carbon Filter Straw Refill Cartridges. Using activated carbon filtration, they reduce chlorine, odours and other impurities for cleaner, better-tasting water. Each cartridge lasts up to 150L (depending on water quality) and is easy to replace, so you can enjoy purified water on the go with your frank green Reusable Bottle and Straw Lid. Key features: Available as a 3 Pack Uses activated carbon filtration to reduce chlorine, odours and impurities Improves the taste of tap water Each cartridge filters up to 150L of water (depending on water quality) Simple to install and replace Designed for use with the frank green Water Purifying Carbon Filter Straw BPA-free and made with FDA & EU-approved materials