Aarke Purifier is a patented water filter jug in glass and stainless steel*. Our water filter pitcher makes your tap water cleaner and more pleasurable to drink. The filtering technology is developed in collaboration with BWT and features a refillable steel filter cartridge and filter refill granules. The granules are poured into the cartridge and changed every 4 weeks. Two filter refill granules options are available: Pure and Enriched. Scroll down to view which contaminants they reduce.