Designed to be equally useful whether there is water pressure or no water pressure, the Aquacera LP4 Gravity Water Filter with Fluoride Option. Is a gravity-feed water filter that makes use of Aquacera’s CeraMetix candles to provide excellent filtration that removes nearly all pollutants from your drinking water. If you are looking to filter fluoride you need to choose the CeraMetix Filters. Notable features of this filter include: —Requires no pressurized water supply; water is poured into the upper chamber and pulled through the filter candles into the lower chamber, fully filtered. –High portability means you can take it with you and use it anywhere in the world. –Manufactured from FDA-approved High-Density Polypropylene (HDPE) which is durable and lightweight. –The upper and lower chambers hold 3.5 gallons apiece.