Do not let the size of the Travel Berkey fool you; this is one powerful purification system. Because it contains the exact same purification filters as all other Berkey systems, this unit is packed with all of the same contaminant reduction abilities of its larger sized siblings. Portability is a convenient feature that makes it possible to bring this compact model with you wherever you go. Backpackers, mountain ranchers, fishing and hunting guides as well as mountain climbers and hikers all use the Travel Berkey to set up base camps. The unique micro-porous filtration ability of the Black Berkey purification filters allow users to take water from most outside sources like streams, lakes, ponds and rivers and convert this questionable water to purified drinking water. Suitable for groups of up to four people. Also included are the Fluoride Filters and Berkey Sport Bottle. The Fluoride Filters reduce the amount of fluoride in your water by 95% for up to 1,000 gallons per pair. The Fluoride Filters attach to the bottom of the Black Berkey Filters and work as “post Filters” hanging in the bottom Canister of the unit. The Sport Berkey Portable Water bottle is the ideal choice for a personal traveling companion – featuring Berkey’s exclusive IONIC ADSORPTION MICRO FILTRATION TECHNOLOGY. The Sport bottle’s filter is designed to reduce or remove many harmful contaminants from questionable sources of water, including remote streams, lakes, stagnant ponds and sub-standard water supplies in foreign countries where regulations are non-existent or not enforced. The Sport Bottle’s included Filter will produce 100 gallons (640 refills) of filtered water before needing replaced.