Specification Filtration technology: Binchotan Japanese Charcoal Water Filter System  Weight: 150g Duration: 6 mos In the early days, people used charcoal to purify tap water. It is compelling in eliminating a bad scent and taste in the simplest way possible. You also don't need a special filter—just a water bottle - to enjoy great-tasting water with BLACK+BLUM Charcoal Water Filter Sticks.  Key Features There are four charcoal filter sticks in each box. By boiling the charcoal sticks for ten minutes, you can get the most out of their performance even after six months. It works well in any glass or metal water bottle. These natural wood sticks measure 118 millimeters in length and can be used immediately to produce ultra-clean tap water. It promotes healthy hydration with enhanced water taste and odor as the charcoal sticks attract all contaminants.  Why Buy This Finding a water filter for convenience makes BLACK+BLUM Charcoal Water Filter Sticks the perfect choice. Put the charcoal sticks in the bottle or jug, and clean, chlorine-free tap water will keep you hydrated.