The RO-CTOP-PHC is a 4-stage 90 GPD countertop reverse osmosis system that adds calcium minerals to enhance the water taste for people who prefer mineral water. This system's mineral cartridge adds only 100% high-purity calcium carbonate to effectively raise pH in the water for those who desire alkaline water. This light and the compact system was specifically engineered to offer exceptional portability, convenience, and ease of use. Hooks up to most existing faucet in seconds - no installation required. If you want an unlimited amount of bottled-water-quality water that you can take with you anywhere, this is your dream system. Perfect for apartments, motor homes, and retirement homes with capacity up to 90 Gal. per day to quickly fill any water storage container. Enjoy unlimited ultra-fresh, clean, great-tasting mineral water right at home for the best quality water for cooking and making delicious coffee, tea and ice. Save money, time, and hassle of buying costly, heavy bottled water and live healthier with ultra-safe water that is 99% contaminant free. The system is designed to remove contaminants such as chlorine, taste, odor, toxic fluoride, arsenic, lead, and chromium.