*The Berkey Biofilm Drops are made in the USA
 
Product will have no seal despite saying so in the instructional leaflet. This will be the case with all current units in circulation no matter where you buy it from. The manufacturers are aware of this problem and looking to rectify it.
 
Berkey Biofilm Drops are used for storing and maintaining pure, fresh water
Scientifically engineered and patented  Copper-Silver Ion solution in the defense of biofilm related bacteria in ceramic water filters, carbon (charcoal filters)  and water storage containers
Especially formulated for use in harvested rainwater containers, long term storage water containers and for use in emergency preparedness and disaster relief
May be used with any type of filter media but works best with Black Berkey Purification Elements 
Extends the shelf life of water being stored for up to 5 years
Extends the time between element cleanings
Eliminates the need to rotate stored water every six months and keeps your water fresh-tasting and odor-free
Simple and easy to use
Claims are based on independent testing and peer reviewed scientific research and have not been reviewed or evaluated or approved by the EPA